Looking to buy a dozer. Right now I have excavators. I’ve only run smaller dozers before but looking to buy something for myself. I do excavation work, land clearing, house pads and I have 50 acres of my own I need to rip a house pad and rip my pastures for better drainage. my options I’m looking at now are a D8k for 55,000. Machine runs good, undercarriage is about 70 percent. Pins need to be replaced sooner than later. other option is D9n for 50k. But has a cracked head and need some other work as well. any ideas? thanks!
Those sound like very large machines for moving, unless you own or have access to a heavy float? What type of soil are you ripping? Perhaps a D6 size would be adequate & much easier to move around?
Located in Hawaii. The transportation for either machine is pretty similar here. I need the 8 or 9 to be able to rip the lava rock. some more background info on the D9n, apparently the back half caught fire a few years ago and they replaced everything on the back, new valves, hoses, seat, all that stuff. Then they blew the motor and put a reman motor in it, ran that for a few months and then overheated again and guessing that the head is cracked. It runs good and doesn’t miss except that the water just blows straight out the exhaust. I’ve read some other stuff that mentions the Ns were always trouble so wondering if I should avoid that project all together
The 8K has a D342 engine. They are getting pretty slim for some parts. The 9N has a 3408 still lots around. What is the serial number of the 8K ? that was a machine which had a lot of updates to it. It was a souped up 46A. which cat spent 7 years improving. 9N was a 8L with longer undercarriage and a paralagram ripper instead of the 4 barrel hinge ripper. The 9N will be a far superior rip cat over the 8K close to 13K heavier and most importantly, suspended undercarriage.
I’m not sure of the 8k serial number. I understand that the 9n will have much better ripping ability as well as be able to move more material. However not every situation I will be in I will want the extra weight that comes with. As far as machines go though it sounds like the 8k was basically upgraded and thought about for many years to get to what it is, however I have heard that they have something fail in the engine that drips oil pressure? And the 9n seems like the youngest generation of that style and has its own issues. If you could pick between the 2 machines what would you pick? The 9n could have a lot more going on then a cracked head but will never know until it’s too late. The 8k is a bit over priced but currently running, although it too could have major issues without knowing
I love D8K’s and D8H’s and I’ve had about 11 of them at last count. But,no more. Engine blocks are very scarce in the UK (they may be easier to find in your part of the world?).Other parts are getting harder to find allthough non oem parts are quite readily available. I’d have thought D9N parts were readily available and they were a good tractor as far as I recall. However,the D9N you have in your sites sounds like a lemon to me. Perhaps,look elsewhere for another tractor. Perhaps a nice D8R?.They are a world apart from an old D8K and would give you the weight and rip ability factor you require without the higher running costs of a D9. Just a thought
in your experience with the d8k is there anything in particular that I should make to check before buying? Any thing I should walk away from the deal if I notice? appreciate the advice!
Here's a little factoid for you ,I was at the Cat store last month and the engine bay had a D342 engine almost put back together. I asked about 45 and the shop boss said at 55k and not put back in. And this was just a heavy overhaul not a blowup. You are looking at a 40+ year out of production machine. Bob
There is a new D342 complete engine for sale in northern Ca. looks like ex military. $33000.00 been for sale for some time. i would have thought it would of sold by now. Kind of shows that most 8Ks are not in a high use or need application now. I owned one for a very long time. They are a very good machine if maintained well. Now most are very tired. Cost of repairs are high on them. Not a modular machine. Transmissions, rear ends and finals are high labor projects. If I were considering one, component hours, serial of the machine is big. What updates does it have, total frame hours. You could be looking at a 30 to 40 thousand hour machine. Keep in mind the design of that tractor put lots of working stress directly on final drives. The high drive machines frames have a longer life span because of the design. The High drives cost to remove components is much lower. Example 8K final 40 hours to r and r. High drive 2 hours. Transmissions and rear ends are the same ratio. They were a great tractor in their day. I know a couple of big dirt contractors who had around 40 of them at one time. But the time for them has passed. I agree with Nicky, we had 8r great tractor. You can find series 1 machines for a good price.
We have a D8L, basically it’s the older version of the D9N. It’s a whole different class of machine compared to the flat track D8. The 3408 engine seams to be good overall. I believe it shares a lot of parts with the 3412 and there are a lot of those still running every day.
And with all this good info, why the crazy high prices for 40 plus year worn out high stressed major parts, dozer like a D8K or H? I've seen some real messes with some crazy prices.
I think they are just too old really. If it’s a hobby machine or a show machine,then fair enough,but other than that,they just aren’t for me anymore. They are just as expensive to repair as newer ones,but the resale peaks at some point. I’d rather spend £50k repairing a D8R than spending that money on a D8K. Hope that helps sir
Are the machines on the big island or over here on the main land? Anything there is going to be beat up real hard because all they do is rip volcanic stuff. I did a job over there a couple of years ago where they used ripper shanks on the end of excavators instead of the big dozers. Apparently ripping with excavators wears out the ripper shanks and not all the undercarriage at the same time. I have a friend in Hilo that might be able to give you some direction. Send me a PM if you would like his phone number.
Thanks for all the info everyone. Options are few and far between over here unless you want to bring something in from the mainland which means at least $20k just to ship it. and usually if people are selling a newer machine they probably beat the hell out of it and still want a premium
Any one there you can hire to do the ripping for you? Bob
Nicky has a very good point. No matter how much money you put in a 8K it will only be worth so much. Like around 50,000.00 When I finally made the decision to replace the 8K it was based on looking at PMing components and not increasing the value of the machine. I needed to do the finals and rear end again. With a cost around 40,000.00. It made more sense to sell the machine 55000 take the 40000 and put toward a 8R series 2 machine. which at the time was the current production tractor.
I was quoted 25k for the work I need done at my house and I have 40k of work for my business through March so I figured I might as well buy a machine to expand my capabilities instead of throwing the money away
thats very true. Would you guys consider the 9n worth it even if I have to put 30k into it after the 50k purchase price?
I don't do dozers, much less big ones, but I'd have a hard time buying a riding lawn mower from people with as bad of luck as the 9N sellers.
Yes.It’s worth a look
In theory,you have $65k of ripping work currently on your books and a D9N that may stand you at $80k when you’ve tinkered with it. You’ve then got the potential to take more work on with the tractor or sell it. Either way,I can see your idea working unless the thing breaks down in dramatic fashion.Even then,a D9N is worth fixing,a D8K probably isn’t. As long as you’re comfortable in having the money to carry you through the ripping project and subsequent contract work afterwards,your idea on buying the D9N that’s allready on the island,and fixing it up,seems a good one. I wish you well with the project.
Thanks all for the advice. Will see how everything plays out…
Good luck and keep us posted.
Well the d9n ended up not being for sale…. Smh. Bought the D8k and just had it hauled to my site today. Serial number starts 77v. Anyone have an idea on year of production? So far so good, need to replace some of the hydraulic cylinder seals on the ripper and some loose pins on the blade. At least I have my 320b on the same job right now. If anyone has any things to watch out for or be careful of with this machine let me know
When I was a young in the 70's I ran a 8K 77V & I believe that one was a model year 1975. Is yours a straight tilt blade?
According to my information, D8K started in 74 and went thru 84. FWD
yes it’s a straight tilt blade
Don't get it hot. It's easy to crack a head. If you're working on a slope, overfill the transmission with 7 gallons to avoid a wild ride backwards. Blade brace pins and cotter pins can be purchased aftermarket. Pull your transmission screens and clean them. Change your filters, with emphasis on inner air filter, transmission filters, fuel filters (clean fuel filter screen) and final drive filters. They don't tend to get much love. Pull the fill plugs on the finals and stand back. If they don't shower you with oil, your duocone seals are intact. Changing the final drive fluid is cheap insurance. Prime the final drive pumps before using if you change the fluid so you don't damage the finals. Pull the floor and grease the u-joint. If it's damaged, replace it now before it gets any worse. Get an owner and service manual which explains all. Clean the radiator and belly pans when you get a chance. Eventually you should determine if your cross tube has been updated. The original hose design was changed because it would brake and spray burning oil on the operator. CAT will do the upgrade for free if you remove the cross tube and take it to them. I don't remember if they will do the R&R or not. These are some of the things that get overlooked in a normal service. If I think of others, I'll update.
Here is possible find free army manuals for d8k https://www.liberatedmanuals.com/all.mpl
As Check Break says,overfill the tranny by the bucket full. A D8K will go forever if……… 1. Keep a clean radiator with roaring fan belts. 2. A good tranny pump with a good suction line. 3. Too much oil in the tranny is good gig. 4. Don’t start it up and expect it to just go to work.Let it idle and have a cup of tea or a smoke before you think of pulling the throttle back or engaging the tranny. 5. Don’t switch it off for at least 10 minuits (ever). 6. Repeat the above. D8K’s are a great tractor if you give them abit of love and care.They are simple and highly effective beasts. I love them.
The K needs fuel twice a day as they love a drink, if you run the engine out of fuel with a hot motor expect a head to crack as they need a steady no load run down after working hard for you, its a good thing to fuel fill them with the engine running a bit above low idle after work to reduce the engine temp' before shut down, this should take 10 mins or more but cheat on this point at your risk. tctractors
thanks I really appreciate the advice!
thanks I really appreciate it! All these tips I’m sure will help keep this thing alive for a while longer.
Soooo machine is running good so far still need to replace the pins and some hydraulic seals. Thought you guys might get a kick out of this though…. First job I’m on and the machine fell in a lava tube… floor of the cab was level with the ground outside, machine was held up by the blade and ripper,luckily I landed straight in on a pile of material cause in either side of the machine it just went down to darkness, some big boulders luckily lodged themself under the front side and was able to climb out, after changing my pants of course….
I can think of some choice words for the land owner if you weren't warned of that possibility before accepting the job. Coal mining regions have that exact same issue and I know of two times where only the size of the machine saved the cost of a funeral.
Is it on to "plan B"? What method do you use when you come across one of them lava tubes?
I’ll probably end up opening it some more with my excavator and then moving most of the greenwaste into the hole and making their house pad on the back section of the property. I told them to think about what they want to do though and let me know because I will have to adjust price with all the extra work of moving greenwaste again and the hazard now
Reminds me of the rural myths that we used to hear in my childhood about people disappearing down old unmarked well shafts that had been filled in at some time and then settled with cavities just waiting for a dog or some kid to vanish into years later. They didn't have 30 ton excavator to stuff it further down back in the day, but how far down do lava tubes go and can you fill them without settlement issues later? Cheers.
Nice to see you’re new D8. Keep us updated please as i’m enjoying your post
Ditto, good to see an 8k working
Dozers going good so far. Been ripping some hard rock for house a house pad, man that ripping is an art… the cat manual on ripping had some good pointers. got 2 things to figure out at the moment, any recommendations for where to find aftermarket brace pins? Cat wants over $400 per pin…. Part #s I got from car are below. I asked uncle google for them but he didn’t have any in the searches… 1j6476 5s7933 also white smoke in the exhaust, from what I read most common is unburnt fuel, any recommendations on troubleshooting that? Won’t let me update a video, tried to upload a picture but hard to tell in the pic. Doesn’t warm up and go away, comes in puffs along with the acceleration
They run pretty much horizontal. Big ones can be 30 or 40 feet in diameter. There is one on Mt. Adams in Washington that has a couple of skylights in it, that let the winter cold air settle in. There is water down there and it makes thick layers of ice that last year around. https://www.outdoorproject.com/united-states/washington/guler-ice-caves
Are you sure those are the right pin part #s? I couldn’t find them on the cat site..
Regal used to sell the pins. They still have a store in Knoxville. Otherwise try American Crane & Tractor and Costex.
im not sure. I don’t have a parts book yet, those are the numbers the person at cat gave me over the phone
1J6476 Comes up as a Rod Asembly. 5S7933 comes up an Idler Gear. Methinks someone gave you wrong numbers...............
thanks Nige, any chance you can give me correct numbers? It’s a D8k 77v I need the 4 pins for the diagonal braces and the 2 pins for the brace that goes straight across the blade I appreciate the help either way!
Does the blade have a Serial Number tag on the top RH corner on the back side.? That would make it far easier to identify parts.
no I don’t see a serial tag. Below are pictures of the numbers off the cross brace though. Hard to tell exactly what they are but one looks like 8j2901
Here's a setup of the arms on a typical 8S push arm setup, 60V-prefix. This may or may not be the blade on your tractor. There are a dozen or more different S/N-prefix ranges of 8S blades out there. Looks like something got lost in translation. Your 1J-6476 Pin is actually a 1J-6746 . The 5S-7933 Pin is actually 5F-7993 . The 8J-2901 bracket is part of the 8J-2914 RH Strut Item #17. #3 is the Serial Number plate. Even if it has long gone there ought be a S/N stamped in that location. Look for the signs of where the two rivets #4 holding the plate should have been.
Crazy. Good work, people. (Few. Beers tonight)
Nige, thanks for taking the time to put that up. I looked in that spot and don’t see a tag. In order to see something stamped I would need to scrape off a lot of layers of paint. with the other numbers lining up on the braces and my dyslexic pin numbers would it be a safe bet or are there a lot of different pin sizes on different blades? Also a friend mentioned having a machine shop around here make the pins for me since the holes are oversized from years of someone banging around, a couple of the holes are now a bit stretched out, thoughts?
Generally speaking,you may want to save your money for more serious issues.A lot of play on an old D8K blade is common and easy to get used to. You might find the sloppy blade better than a tight blade in that volcanic rock.Looks pretty hard ground and abit of give in the pins may offer some forgiveness in the old tractor.A tight blade might find a few week spots perhaps?
It's more important that your brace pin ("BP") stays in the bore rather than it be tight. The BP has a cotter pin ("CP") underneath to keep it secured. Yours may not, the CP being pulled out and/or the BP pin hole being worn away. We modified our BP-s and no longer CP-s. If there's no hole for a CP underneath, it might be a good idea to weld something on top or below to keep the BP in the bore.
Fun stuff bcole4! I have been on the big island several times with family and naturally would watch the big iron ripping lava.
thats a good point didn’t really look at it that way before. Thanks for the input
Ya the cotter pin hole is worn down and clogged with rock. I did weld a piece of rebar across it last night to keep it from slipping down, so far so good. thank you
It’s definitely fun, I’ve only cleared lots and done septics with my 320 before and run friends dozers here and there, so the dozing is a fun new world
Anybody have any recommendations on a place to start for the white smoke? injectors?
As long as the push arms are not hitting the tracks and you are not doing finish work no big deal. The diagonal braces have adjustable ends unless they are welded up. you can take a lot of the sway by adjusting them. Bob
That motor doesn't have injectors as such it uses injection pumps and nozzles in the pre cups. Loosen an injection line to find which cylinder is missing. need more info as to when motor smokes. Bob
not complete finish work but need to be able to build on the sites when I leave. yes the braces have been welded up already…
seems to smoke a small amount pretty consistent while running however there is a puff of thicker smoke rhythmically. how do I track down missing cylinder by loosening fuel lines? thanks for your time and knowledge!
Do you realize how hard it is to trouble shoot by someone else's description ? Set the idle where it smokes the most and loosen the fuel lines one at a time and only one till it quits missing. Are you running it with the governor opened up? Bob
yes I do and that is why I greatly appreciate you even trying to help me diagnose or where to start. ok I will try this on Monday when I get back down to my site. sorry, but what do you mean by governor opened up? I’m assuming that the governor opened up is different from using the decelerator to control engine speed
Your problem with it smoking and fluttering could be a worn c spring dampener at the back of the injection pump in front of the governor, it helps smooth out the pump between lobes.
tried this today. Loosened one at a time until fuel was spewing out. Didn’t seem to make that big of a difference on any particular one. Do I need to loosen all the way or just partially like I did?
ok thanks for the info. I have my service manual on the way and I will look into it Do you or anyone else know what this line on the back of the fuel pump is? It comes out the very back and connects to the other side of the engine on the air intake. It has a large hole in it where the throttle linkage rubbed it raw.
Thats the air pressure line to the fuel ratio valve, fix it. If each cyl. sounds the same with the line cracked probably not the injection pumps. Bob
could this be cause of the white smoke because the ratio is off? Also one of my haulers said it sounded like I might have a burnt valve. Is this something that needs to be diagnosed/fixed ASAP or is this something that can wait a bit? again, thank you all for your help I greatly appreciate it
cracked open the finals today (well one of them, other side broke my ratchet) and it was filled with excess oil. Didn’t shower me like you said but was pouring out the fill plug. Is this the duo cone seal and what does it mean for me?
A bit more info… Wasn’t able to open the left side yet but found a pin hole leak on it, photos attached. oil coming out of left side is yellow/clear. Oil coming out of right side is dark brown/black talked to a friend who said could be where my tranny oil is going and that he just leaves his right side capped and doesn’t ever drain it
Keep an eye on your transmission oil see if it goes down. You need to pull both drain plugs and check for swarf, don't really need to drain them. Look under the tub where the rippers are attached and check for cracks. Don't overfill the transmission and clean the vents on the top of the brake housings . Kinda looks like your track rollers are wore out. Bob
Very common to have final drives over full on old D8’s.They weep through the seals that may have hardened off. Obviously,it can be other reasons,but I wouldn’t worry about it.
Yes. Means that oil is passing from your bevel gear compartment at the pinion and draining into your final. As Nicky says, it's not uncommon. Will be worse on uneven ground. Sounds like the duo cone is not completely shot or oil would have shot about 12" up and out of the final fill hole when you removed the plug. The fill plugs are best removed with an impact, slowly. Kind of hard to do with a ratchet unless you were just in there. For now, just drain them off and keep an eye on approximately how much is coming out over what time period. You're not going to want to replace the duo cones until you need to work on the brakes or cross shaft.
Why is the oil coming out there? That should be a thick casting there. Or is that a drip coming down from higher up?
Thats where the intermediate gear and bearings are . Seeing as how the plug for the bearing dowel is leaking kinda makes me want to check the sump for parts. Maybe even change the final drive filters. Bob
it’s definitely coming out from there. It’s a pin hole in the metal
I’m almost done with the job I’m on and then taking the machine to my ranch to do some work, I will some major servicing while it’s home. Any thoughts on the major color difference between the final oils?
IF it's a pinhole, jbweld it and put a slight vacuum long enough to suck some into the hole, then forget it. use a bit of brake cleaner to clean the hole with vacuum applied first. if it's a crack, then you have other issues.
I just can not understand the crazy prices on all the old dozers. They have already paid many times for themselves, over the original cost from when brand new. They all have high time and likely fatigued parts, I have seen them with cracked out main frames. Then there are the jippo fixes on engine blocks, and things like welded transmission planetary carriers and the list goes on. Leaking at the rear plate caused by all the inner bevel gear case to rear plate welds cracked, I've seen it all. Its all just a lot of money for a pile of potential scrap IMO. The only old D8K's that maybe worth it are some of the ex military ones that show up on occasion.
had the same thought this morning minus the vacuum part. I put some jb weld on there so I could get through the day without dripping money on the ground as I go. Held up for the day at least. and yes it is a pinhole not a crack
Likely a case of pushing lots of extremely hard and abrasive material. Lava does things like that. Make a steel patch, clean the area around the leak with ether and weld the patch over the top. Oil color I would guess is someone changed oil in the side that is clear. Left the old in the dirty looking side. She is tired is all. You probably paid close to what it is worth so you can expect those kinds of problems. If that is the worst so far, you are doing fine.
What color is your transmission fluid. Dark brown/black or yellow. Which final is which color. Black transmission fluid might indicate engine oil contamination. If it's getting into the final with the dark oil, that's the source of your color, otherwise, as said, the final with the dark oil is running oil with hours on it. If you transmission fluid is yellow, the final with the yellow fluid might have transmission oil in it that's leaking out at a fairly rapid rate, or it could just have clean 50wt in it.
thanks for the words of encouragement. I appreciate it
trans oil is yellow. Left side final is yellow out of the pin hole, wasn’t able to crack it open yet. Right side is overfull and dark brown/black
Be careful not to overthink it and loose sleep.As John C says,it’s an old lady with various leaks and drips,stutters and stammers.Abit like an old Aunt.She’ll still be well capable of baking you a good batch of cookies though. Yes,your pin hole could be your pinion moving about abit over the last 50 years and that dowel acting up,but it’s most likely corrosion and old age.I’ve seen coal tractors rot around that area. Treat it like a scab on your elbow,keep it clean,patch it up,and change oil and filters in the finals. Keep a very close eye on the trans dipstick for a few months,especially if it’s parked up, and keep refilling the tranny until the finals have found their level. Try and enjoy playing with the old D8 as it will soon let you know if it’s sick,and in many cases,catching it early will only cause wallet stress sooner.I’ve had many old D8’s work with faults for years and years. Doing things by the book,will most likely bankrupt you on an old tractor,and it brings us right back to the start of the original post. We are all on a wing and a prayer with old kit and,quite frankly,new kit.
Thanks I appreciate it, since it’s new to me and the dozers are new to me in general I’m just having a harder time figuring out what is necessary to fix now, what can wait a while, and what is normal for this old girl. I appreciate you guys all taking the time to give your input
I think I found something that is very concerning now… checked the magnet for the trans and along with regular metal dust there is large pieces of what appear to be a bearing… I will post pictures in a bit when I get home. not sure how long it’s been in there, trans runs normal, nothing has changed from when I bought it at least. Is this a cease work order until I can pull trans and get a better look or if it’s been running ok so far can I continue on for now?
Certainly pull the filters out and cut them open.
Here are some pictures of the bearing parts in the magnet.
As old Nicky says don't worry the old small stuff there are 29 more of those bearings in there. Bob
im not super concerned with the shavings and such but the large parts from the bearings I am. a friend told me that it could keep running like that for a long time or the next time you drive it it something major could explode inside the trans because the bearing is gone, so basically I have to do the labor of removing the trans and fixing it either way but if I do it now, it will be less money in parts. Thoughts? I have the machine at my ranch right now and I can pull and rebuild before continuing, I just don’t want to blow up the trans and have to completely rebuild if I don’t have to
It’s not pretty. You’d like to think that the last time it failed,the screens were cleaned up. You have to look at the filters and cut them open.
That’s the same filter out of one of my tractors that I’ve serviced last week.It’s suspiciously clean,but it does get tranny filters every 250 hours. I’m thinking you have abit of pain coming your way unfortunately. Allthough it’s little consolation,it hasn’t failed yet and could easily have happened to the D9N you were looking at. Allthough unlikely,it’s possible that the previous owner,or past owners haven’t bothered cleaning things out properly over the years after past failures.It does happen. I wish you luck,but cut your tranny filters open anyway.
There's the issue. It would be a lot different if you knew that screen had been pulled and cleaned say 3 months before you bought the machine. Clean the magnets & screen, put the machine back to work, and see what accumulates on the magnet after 50 hours or so..? I do see a transmission overhaul at some point though, maybe sooner rather than later. The "half moon" and the other smaller similar piece are parts of a thrust washer (#27) from a planetary set inside the transmission. The needle rollers (#30) are probably from the same planetary gear that lost the thrust washer, likely the bearing failure took out the thrust washer. As mentioned above there are plenty of those bearings and washers in that transmission. The parts list says 42 of each but the illustration I found may not be exactly the same as your transmission.
i called the seller he said that the last time he checked the magnet was about a year ago. He said he changed the trans filter about 3 or 4 months ago though so if I cut that open maybe I will get a little bit more info out of it. I did find a lead on a potential reman trans that someone has for sale. They told me it’s a new reman trans that they bought at a auction on Maui and it’s been sitting in one of there containers never installed. He said when he bought it, it had a tag that had the caterpillar logo and said D8k reman trans and had a little bag of gaskets for reinstalling it. He thinks that because it had cat logo it was a reman done by cat but someone else told me they never heard of a trade in program with cat for that sort of thing. Either way they want 8k for the trans, are willing to let me open it up to take a look inside, and give me a 1 week warranty. so my options right now are to rebuild my trans, run my trans until something else happens, or buy this trans and run mine until it totally breaks down and then swap this reman one in
Can’t beat having a spare tranny about the place. You need to open the filters. 8k is a good price for a tranny if it’s as described. It’s far better repairing a tranny that’s not failed with a bang.
8 thousand would be a damn good price for a spare trans seems to me cat reman tags have some information serial # that might be traceable Yes Cat certainly handles exchange units so the story is plausible
First thing the air boost line from the inlet manifold to the Air Fuel Ratio Control means the engine has not been running correctly due to the rack travel of the injector pump being restricted, repair the line and run a stall speed test, the F/Drive with the sweat marks is most probably from damage caused by a rock or stone punching into the case as the frame moves about, this is not uncommon, the screen scrap iron thing is telling you of a fast coming rebuild job, don't think you can just stuff another transmission in the case and drive off as the lash on the Bevel Gear will need checking, if it's tight or to loose on the lash you will soon be into a nightmare, if you do pull the transmission out you might as well pull the torque out and check the bearings and the 2 shaft bushings for correct fitting, these bushings are often fitted back to front and effect the oil feed, the D8K transmission is not the same as the earlier D8H unit as it has an extra plate in the Forward pack (4 instead of 3), looks like 2 or 3 weeks of work ahead by yourself. tctractors
After all these years of reading on HEF I am still amazed at the huge amount of technical advise anyone can get here. This thread is good example of it. I follow tctractors on Facebook. It is quite an interesting Facebook page.
This is the problem in a nut shell, where do you stop? Transmission rebuilt check. Torq convertor rebuild ? Coolers cleaned? Bevel gear checked, adjusted, maybe repaired. And while we are there steering clutches and brakes. This is the problem with old equipment. It becomes a money pit to get it right. And worst of all the value of the machine does not increase much. I realize renting seems expensive, but it does have some advantages. You get the right machine for every job. My first machine was a D8K, I made that machine do work that would have been more cost effective with a different machine. Even if you do all the labor and you have the tooling, parts are expensive for CAT parts. You can go non oem, but I for one have never had good luck going down that road.
I would worry about damaging or causing further damage to the carrier within which the bearing failed. Those things aren't cheap. I kind of remember the Italians made one aftermarket. Otherwise, it's figuring out how to repair yours or buying a good used one. There's something to be said for digging in now before catastrophic failure. You'll spend a day or two cleaning the bevel gear compartment after a catastrophic failure, far less if you catch it early.
The thing that has possibly saved the day is the damaged air boost line, if the engine was getting full rack lift it would be sending big chunks of shrapnel into that magnet screen, on those screens you always get an amount of fine silt like wipe stains on a paper towel, but that screen in the picture looks like its fallen in a skip of engineers waste, a few more of those small rollers are just waiting to jamb between the the teeth in the back carrier (Most Probably), when you see that amount of junk hanging off the magnets it's a mighty good clue it's not break in fluff, the Transmission is 1 Job with checking the torque is more possibly a time thing with a gasket and a few O rings if your luck holds, the bevel gear lash needs to be checked more to establish it has some than anything, the pinion on the power shift is floating, the drain plugs under the steering clutch case are often blocked up with bits of band and junk and well worth cleaning out, it's a wet weather job and not really a bad job, steam cleaning things make the task a lot easier, best of luck that Man as he has 10 to 15 days of entertainment ahead, I would not buy anything until the bits are stripped right down and component checked. tctractors No second hand D8 or 9 ever comes in mint condition, they always want something off the new Master.
thank you for taking the time and giving me your input. this forum really is an incredible place right now my plan is to pull all the floor out, clean everything up real good, drop the trans pan, move the dozer 20’ to where I’m gonna drop the trans, take trans out and break it down to see what the damage is inside, then decide whether I’m gonna replace what I need to or look into the other reman trans while it’s down I have some other TLC and paint I need to take care of on the old girl. I appreciate everyone’s input and will keep you updated as things progress
One more question, for now…. any preferences on rolling the top back and pulling trans up vs driving up on blocks and dropping trans down then pulling out the back?
I usually took them out the top as I seem to recall they wouldn't clear the swing frames without pulling the torque converter. I also had a tire truck knuckle boom with a line that allowed that without having to pull the ROPS. Our friends with the different accents will probably let you know the best way. Also with that kind of possible damage, I would recommend pulling the converter and having a look see.
As said above sir. Top exit,and torque out same time. Take a look at the engine mounts once you’re stood in the void.The right hand rear engine mount likes to migrate into the chassis abit.Not a big expensive issue to fix,yet it can cause your torque and tranny to run out of line if left unattended. Please keep us updated. Thanks for posting,and good luck
The Transmission needs to exit upwards, its a tight little job to tackle with the Cab off, I would never bother to even try with the Cab on, it would be the best idea if you stripped all the tread plates and any covers below the fuel tank off, then remove the seat with base plate and both belly pans to steam clean as much as possible, all the valves , pipe work and drive shaft have to be removed including the scavenge pump if you pull out the torque, allow a day in cleaning as the effort is well worth it, I always start the engine up and pump the trans' oil out with a hose hooked into the filter top, there is still lots left in but it's a lot easier to handle. tctractors.
Do you have a cab stop bracket like the one in this picture (below the left rear ROPS post) on your machine. You can tilt the ROPS or EROPS back and it will bottom out on this stop. Enables you to access the transmission and the brake covers. I don't remember doing a transmission without opening up the entire bevel gear compartment. Pull the fuel tank (clean it out while it's on the ground) and steering clutch covers. It's time to check the cross shaft, replace the brakes and probably pull the pinions and replace the duocone seals. A whole lot easier now when she's opened up. This also allows you to clean out the bevel gear compartment if there's more scrap iron (I like Tony's definition) in there.
Is nobody going to tell this man he needs to stop right where he's at, snap a few pics, and hope nobody else on the island reads HEF? This IS going to escalate from a bad dream to a nightmare, and onward to a downright tragedy. Cut your losses, man. You finished your paying gig, quit while you are ahead. Just my $.02.
Post #105 he says he's going to pull it forward 20' and take it apart, sounds reasonable to me. NOW I get it, you're telling him to sell it as is. Depends on if he wants to be an operator, or if he want to learn how to work on an old Cat...
I'm just trying to be a voice of reason, lol. Nothing wrong with learning how to work on old Cats.....this is going to be a VERY expensive and painful schooling, for everyone.
Any way about it he's going to be working on a machine. The next one will do the same thing. There's something to be said for 7500 hour components you can rely on than those you know nothing about. Don't forget he's in Hawaii, there's a limited number of machines available, and the cost/logistics of shipping a machine to Hawaii these days is not what it used to be.
becole4, I could suggest that you look at an old line of mine in Shop Talk headed Caterpillar Sprocket Removal it's worth hunting through as it has lots of snaps of D8's Calved Down, tilting the Cab if it's a modular (EROPS) type is handy but it's only 2 more bolts to undo to lift it clear off, I never bothered to tilt them just lift away off the Tractor was my choice but we all do things different. tctractors
HeavyEquipmentForums
Beauty is in the eye of the beholder. Good business is in the pencil of the guy doing the figures and writing the checks. There was another guy on the island I think south of Kona that went through a D9 awhile back. The conversation went somewhere along the lines of it was cost effective to repair what he had against buying a different machine, maybe newer, but with the same risk of expensive repairs.
Shimmy, you just can't resist can you . Bob
I know where you are going with this, but I'm not taking this position based on an assumption of capability. A recoil replacement is quite a bit different than what this 8 is going to require, both financially and complexity.
i don’t believe I do. Was told to roll it back and place a block between the canopy and ripper cylinder to rest it on. I was planning on leaving brakes, and duocone seals for another time. Financially I can do transmission but don’t have a lot of wiggle room to do everything at the moment. In the future I know it will be work to open everything back up but it is a bad idea to not do everything now? It seems there is an endless amount of work that “can” be done, but as said before that will bankrupt before can get any work done
Thanks for all the input guys, As far as selling vs fixing goes… I’m on the same page as check break, with the very limited amount of machines available as well as my budget, no matter what I am going to be working on a machine whether it be this one or the next. As far as I’m concerned at least I will know the state of transmission after rebuilding and, fingers crossed, won’t have to worry about that for some time. My theory and from what I’ve learned talking to people is as long as I stick with it and fix what I need to and stay on top of maintenance as I go then the machine will pay itself back to me and then some. It’s a matter of not giving up because when you tap out you lose everything. A friend described it as having a second wife, you need to give it some love and tlc to keep it going or else all hell will break loose and she’ll make you pay for it in the end… it seems these 8ks are a good work machine for the ranch work and small jobs I want to do as long as I maintain things and NEVER let it overheat.
What you really need to do pull the 5 drain plugs across the back of the tractor and see what is in them. You don't have to drain all the oil but have a rag to plug the hole then put the plug back in. I use a small kitchen strainer to catch the parts in the first gallon that comes out. Then you will have a somewhat better idea of what is going on. Bob
Bcole,it seems to me that you have a total understanding of what’s going on here with the feasibility of the project.Yoyve needed a big tractor,and like many of us in the real world,you’ve not had the luxury of having a million dollars to fork out for a new D9 with all the security of a warranty and a nice r@m contract.Instead,you’ve had to play the hand of cards you’ve been dealt.In this case,you’ve had the joker in the pack dealt to you.It could have easily happened with a 7000 hour D9T of D8T that’s set you back $500k and where would you be then? Instead,you’ve got an old D8K that can,and will be repaired over time and an unknown cost at this point,but you’ll get there in the end,and it will pay you back.I promise you that.Like the wife you mentioned,it will be with you until death do us part. You’re into this now,and when you’re going through hell,you’ve just got to keep going even if it means you leave it in the yard for long periods whilst you’re earning money and carying on with your life.You can pick away at it when time and money allow. Any talk of giving up on it,or selling it for parts,simply doesn’t sit will with my business ethic’s. Keep going with her.
Hi again all, so had some hiccups but finally got the trans pulled out. Was supposed to have someone very knowledgeable help me rebuild it but that fell through. Now I got it sitting on a trailer and trying to figure out my options. a friend of mine recently did his trans for his 7 and said it wasn’t too bad just need to keep everything in perfect order and clean. I’m mechanically inclined however never new to the dozers and haven’t dove into a dozer trans before. anyone on here done the 8k trans before and have any info if it’s something I can figure out or if I should steer clear from it? stuck between a rock and a hard place and don’t have a lot of options
@tctractors is your man, He's already commented earlier so hopefully will chime in again. Meantime take a look through this thread and see if it includes any transmission photos. HeavyEquipmentForums When looking for parts it may pay you to base the search on transmission Serial or Test Number rather than the tractor Serial Number. See example below.
Get a service manual and sit down with it for a few hours at least and get familiar with what you are looking at. On the D8K as I recall the valve comes off first and then tip the thing up on a couple of blocks with the bevel gear in between them. Take the stuff off that is now the top and then the case comes off by unbolting the base. Lift the case off and the planetaries are right in front of you. They are held together by thru bolts. Take those out and they just unstack. They are not difficult to take apart and put together. The trouble is in the details, recognize what is bad, worn out, missing parts or where debris came from. The first one is the worst. After that they get kind of routine.
Good to see you’re making progress. TC tractors has done a number of successful transmissions for me including D8’s.He’s very experienced in knowing what to put back in,and throw away.He knows his stuff and is very concious of the costs of things.I suggest detailed pics that he can study in his own time.He’s on the other side of the world,but he can see things a lesser man (including me) can’t. As John says,get the service manual and get quality pics of all the parts. It goes without saying,bearings are an absolute must.Careful scrutiny of carriers etc is a must.Get the pics on here.It’s unfortunate that you haven’t got an experienced man to hand,but you haven’t,so you’ve got to just do the best you can. There’s plenty of good men in this forum (that will also understand the actual reality of having to make so with less than perfect parts) that can help you. Good luck,and get stuck in.
The hardest part is removing the Transmission and getting it sat on the floor, now its out you can remove all the main case drain plugs and jiggle out any lumps, on the trans'pull down its best to remove the lid and valve block, then remove the oil feed line to the pinion, sit the trans on its end so you can unbolt the outer case and lift clear, now you can see how simple it is so mark all the sections and I use a tippex pen to mark all the speed and direction identification on them, then start pulling things off and stacking things in tidy order, the pinion bearings are pin locked in the case but easy to remove, post a few pictures and plenty of people here will help you sort out the rebuild. tctractors.
Hi guys, thanks for the support, wouldn’t be able to do it without you all. Schemed up a plan of how to get it off the trailer today since my excavator is on a job site and I don’t have a shop. Used a engine hoist to move it to back of trailer, then set up hoist in my shed so I could lift it up a bit and drive the trailer out from under it. Finally got it on the ground and turned over properly.
After all that I was able to get the valves taken off, cover pulled off, and top housing removed. Here’s some pictures of it. As I break it down I will take more pics of everything. So far the damaged I’ve noticed is some the “locks” on the bolts were broken off, and one of the planetary gears on the top clutch is very sloppy
More pics. Hopefully this can help someone else one day if they’re in my shoes and don’t have many options…
Welcome back everyone, man that felt like forever….. so after diving into my trans I found what I thought significant damage to the carrier and planetary gears. Attached are some pictures. Long story short, I ended up tracking that reman trans I had mentioned before, popped it open and everything seemed in good order and truly was a reman. Was able to get that for $7k. Just installed over the last couple days, got all my hoses hooked up. Now I need to check the backlash, any tips or tricks to this? Do I definitely need to track down the dial gauge to measure it? Also a friend told me to open a port on the trans pump when I first get it started to help bleed the air out and make sure I get oil to the pump quickly. Any suggestions or things I should do, or not do, when I fill up oil and initially start her up?
The backlash thing is a fair handful to get a good reading when you still have the steering clutches in place, even trickier with the tracks on, anyhow the idea is to push the pinion forward towards the engine and measure the lash as best you can via the bevel gear, this will involve a long spanner on a clutch mounting bolt, 3 arms are handy to tackle this task and manage to get a satisfactory reading, I always like to re-bearing the cross shaft as it is easier with the transmission removed to set-up the pre-load, the lash adjustment is set with moving the shim stock from the bearing housings as required, the DTI is better at telling you if you are on target than a strip of card that you might think of using, as for venting the transmission pump, well as it's a K it will have a constant prime line fitted, so all I do is prime the pump before fitting, if you want you can open the purge plug on the high pressure filter lid by first cracking it loose then with the engine running undo it with a spanner a small amount until oil starts flooding out, half a turn on the plug will make a mess fast enough. tctractors
Thanks for the reply TC. I was reading the manual and in there it looks like the measurement is off of the pinion, which is the gear coming off the transfer case, am I correct? And then am I correct in that I need to remove all three of the covers below fuel tank as the bearing cages and shims are in left and right side, not accessible through the bevel gear inspection plate?
If you are going to do a proper job you will be sorting the cross shaft with the transmission out and the clutch packs removed, it gives you a chance to clean out the main case, the target on the lash is with the DTI on the pinion, this lash is checked at 4 points around the bevel gear to check for a bent cross shaft and tight spots, most people would just bolt up a new transmission and not think about pinion clearance, some end up with the transmission bolts snapping off or working loose or the bevel bolts snapping, if it was my job I would re-bearing the cross shaft, set the pre-load, fit the transmission, then set up the lash, ending by fitting the clutch packs. there would be a picture of this in the rim pulling thing of mine. tctractors
@bcole4 - A couple of photos of an empty hole............. © tctractors What you should be aiming for before refitting the cross shaft (c/w new bearings - 3rd photo) and before setting the backlash. Note carefully TC's comment regarding the risk of transmission mounting bolts breaking or loosening, or even bevel gear bolts breaking if the backlash is not correctly set.
Thanks for the info and pictures!
The last K we bought had a transmission swap like this. The tranny worked loose from the bevel gear compartment and stripped out the threads. I had to have studs made that extended through the mounting holes far enough to add a mechanical lock nut. Works well since. Wouldn't have had to do that if the prior owner had reshimmed the cross shaft at time of R&R. Best to follow Tony's advice and set up the cross shaft by the book.
You're welcome. They all came from that 47-page thread of TCT's. It was relatively easy for me to find them because I knew what I was looking for. That thread should form some essential bedtime reading for you .............. HeavyEquipmentForums
Yes it is good reading! I’ve gotten 11 pages in, having a hard time making enough room in my head for all the knowledge!
Ironically,those pics that Nige has put up are one of my D8’s Tony did for me.Never been back in there again. Had a D9H on hire years ago that would bust a tranny every 1000 hours or year.The bolts would allways come loose on it first.Was never right
I do feel slightly worried that I have forgotten the fact that I have near every important service tool for flat drive CAT's, it's very hard to work on this equipment without this tooling, I know people manage to an extent but it often lacks the confidence in the finished product, should I apologize for possibly leading events to what might be a tricky spot, it's easy for me as I have done this task many times but this can take a bit of doing as the clutch flanges have to be removed and re-pressed in the case, the top pinion flanges can be pressed off and on in a standard workshop press but Bevel gear work is all in the hole.
I don't think so.Tony The owner of the D8K needs to be made well aware of the potentially disastrous consequences of getting it wrong. It's not simply a case of stuffing the replacement tranny into the hole in the back end and hoping for the best.
Correct.Fore warned is forearmed
Yes thanks for the forewarning it’s nice to know the downside on different circumstances. so I set the back lash on the pinion. Finished hooking everything up and installation. Filled it up, bled the pump and hooked up a pressure gauge to it. now I only get about 100 psi when machine is running and nothing happens when shifting into gear. I don’t know the pressure before doing the swap but is there a reason the pump would only be putting out 50-100psi after? No noticeable leaks where oil is pouring out from. any advice on where to start?
Update: found the problem, the valve inside the priority valve on the front of trans was missing. Removed the cover on the trans and started it to find this out. Unfortunately, either from previous damage or from running it without the pump pressure, the scavenge pump bit the bullet. Was super happy because it was was shifting in all gears and started closing everything up when I noticed trans oil coming out by the starter, did some research on HEF, found a diagnostic with running the machine stalling the converter and seeing how much oil comes out in 60 seconds. Pointed towards the scavenge pump. Pulled the pump off and the gear was sheared off and sitting in the torque converter. Took the pump apart and one of the teeth on the gears inside broke off and wedged itself against the others and the casing making it frozen. Out of curiosity, any thoughts on whether this was previous damage, or possibly caused by the lack of pump pressure anyways I’m heading to a friends place tomorrow to grab a scavenge pump off a parts machine he has and use that one for now. Cat wants $1600 usd for an aftermarket one. I read the article on here between cheap and cat parts and seems like TC supports cheap replacements for this. I’m going to try the used one and see how long it lasts and possibly order another one down the road to have on hand
Inside the Priority valve slug is a filter that needs dinky little Circlip pliers to remove, it's worth checking this valve correctly before you start pump and hose damage? the scavenge pump often seems to suffer damage most usually from removing the Torque with this pump still in place as it snaps off the gear or bends the shaft, the strainer filter will need checking in the bottom of the case, the gear snapping off inside the pump is most odd as this sounds like something was passed into the gear teeth to cause this, it could have been due to running dry of oil but not a common thing to happen, I suppose you just checked that you had an amount of Lash on the Pinion / Bevel gear, as long as you have some movement things will be O.K. to tight will fail fast, to loose will make a bit of Music. tctractors
I will take it back out and check out that filter. Thanks for the tip. Attached are some pics of the broken parts of pump. I read another thread, (I think on HEF), where it sounded like the guy had the same thing happen as me. I’m just happy that it was the pump and not the torque. I bumped the starter a few times to check the cover on torque and didn’t see any cracks. The strainer filter is accessed through the drain plug of the torque? Ya I checked backlash but didn’t do the bearings and all that. I might regret it down the road but for now I need to get operational and don’t have much more to spend on repairs at the moment without getting some work done.
TC- inside the slug I got a retainer ring, cap, spring and plunger. Is there another part inside that needs to come out? thanks!
There should be a little filter screen if its off a K. tctractors
Well guys, as of now I’m up and running! one of the hardest things of the entire project was bench pressing the plate that connects the two belly pans, note to future self: clean it out good so you done have to do it 5 times…. I will let you guys know as things progress and i so greatly appreciate all of your help with this!
Hi all, been running the machine and she’s been doing good for me. Few small things here and there but nothing too bad except for a problem recently…. the last job I was on i sheared the bolts on the master link. I think that some of them got loose and then the last one in there sheared off. Was able to get it back together and get some new bolts back in. now I’m on a new site and the same thing happened. Is there something going wrong? Or is there something I can do to prevent this? Did I not crank the bolts down enough when I put the new ones in? thanks in advance for the help!
The threads inside the bottom half of the master link are now likely to be worn if the bolts were running loose. How tight did you tighten the bolts.? Do you have a big torque wrench.?
I used a 3 foot pipe on the end of a breaker bar and cranked them down with that. I don’t think I have a big torque wrench but I can borrow one if I need to. if the threads are worn is there something I can do short of replacing the link? Can I threadlock or weld something in there?
A 1"-square drive socket I hope.? You probably need a pipe something of the order of 6-8 feet in length to get those bolts fully tight. The spec is 250 ft pounds plus an additional half a turn of the bolt after reaching that torque. PLUS the threads and the underside of the bolt head have to be lathered in anti-seize before assembly.
Ok thanks for the info. I will try again then and hopefully it will stay this time….
Fingers crossed for you but TBH if the master link has come loose a couple of times already it is likely to do so again. It's not just the bolt threads that will be worn it's the crocodile teeth too.
Here is a couple pictures. Are these considered to worn already? is it possible to weld the teeth together after torquing the bolts down properly? or is the only remedy to replace the link?
You need to clean the dirt out of the teeth and use all 4 new bolts. The new bolts should thread into the holes finger tight. Bob
thanks for the tips. Last time I cleaned it all very well also I just didn’t get it cranked down enough I guess. ordered the new bolts they’ll be here Thursday morning
Things are worn in that croc clip unfortunately. To give it a chance,I’d clean everything up absolutely spotless,clean threads up and buy 4 new genuine Cat master bolts.Make sure your grouser pad is spotless too. I like abit of anti sieze on the bolt shanks too for good measure.Torque them down as per the book in sequence.Some of the lads on here will advise better than me how any oil or anti seize will affect the torque settings. I suspect,you’ve one last chance at getting things right here. Hygein is your friend here. Good luck and I’m glad your tractor is up and working.
I would consider no anti seize it can make for some obvious problems later but on a marginal master link we have had some good luck going that route, also that half turn after torque is very important
Thanks for all the input everyone. I have a few questions, 1) there is debate on whether or not to use anti seize, any more info on this? 2) is threadlock an option to help hold or is that not even a consideration 3) what about welding the bolt heads to the pad? Just to help keep them from backing out?
No debate as far as I'm concerned. The specification calls for it on the threads and under the bolt heads. Many people also apply anti-seize to the shank of the bolt. Some would also touch up the surface of the master shoe around the bolt holes with a grinder so that there are no ragged edges for the bolt heads to get hung up on when tightening. (This is actually included as a step in the track connection procedure on newer machines) I don't know if anyone mentioned it but using a blow gun to clean out all the dirt and then running a plug tap down the bolt holes in the master link is also essential IMO to ensure that the bolts tighten correctly.
Trust Nige, I've done it on some 977h's that sat more than ran and obviously are not developing the kind of torque your tractor is. If you get to the point that your buying a new link and pad try it before you do
Well guys better late than never I guess…. here’s an update on my track. the bolt holes were too stripped when I tried to reassemble so I ended up tapping them to a 1” hole and used grade 8 bolts in there The only welder I could get on site was my wire feed hooked up to a couple paralleled generators, I welded the clip very marginally at best, but it held for a while. finished a few jobs with it and had it back at my place doing some ripping and clearing when I of course busted it again. 2 of the bolts came out and the other were only about 1/2 inch into the bottom of the alligator clip and they stripped that part out so I’ve got everything lined back up and bolted together, going to weld it up proper tomorrow and hope I don’t keep doing this to myself… just wanted to give an update and hope you guys are all doing well!
Hi everyone, D8 has been running pretty good and earning her keep. Had quite a bit of water accumulate in the trans oil so I changed it. When I changed the filter I checked the magnet and found some debris… pictures attached. Looks like 2 rollers from a bearing and possibly a few clutch chunks, and a brass rivet? I saved the filters so I can cut them open. I’m wondering it it’s possible that these are old pieces from when my previous transmission was going out that were stuck somewhere in the system and just worked there way to the magnet or if this has to be from the new one? Also my left steering clutch has recently started working much less. I have to pull and hold it to get engagement when going forward, but in reverse it works just fine, thoughts?
Clean the screen & magnets thoroughly. Clean & re-photo all the material above. It is hard to identify some of it because of the covering of oil. Then keep it all for reference (there are what appears to be a couple of lumps of friction material in that lot). Then run the tractor for a month, pull the screen again and see what's in it. It's worth remembering at this point that you stuck the replacement transmission straight into the tractor with no attempt to set the pinion contact or backlash.
Thanks for the reply Nige. Here’s a picture of the debris cleaned up
That bronze-coloured piece looks like a rivet. From a steering brake band friction lining maybe.? I'm not 100% sure if it could migrate from that compartment into the transmission.? Provided all the grey bits are non-magnetic I would say they are clutch facing material. IMO the three rollers are from a planetary gear needle bearing.
And I cut open one of the filters, there’s some very small flakes of shiny metal but not much
Ok so then this could be part of the reason why my left steering is minimal right now. Is there a reason why the steering clutch/brake would work good in reverse but not forward? I had the same thought on the bearing pieces based on what I found on the last transmission, is it possible that there are from the previous trans and were somewhere in the system but only now worked there way to the magnet?
That's a plus. Did you clean out the magnetic screen/filter during the installation of the transmission that is in there now or is this the first time it's been cleaned in a while.?
I cleaned the magnet pretty good but I don’t believe I thoroughly cleaned the screen when I swapped the trans
Anyone have any thoughts on why the left brake works in reverse but not forward?
Yep that is what they do due to the wrapping of the band in reverse, the bands when fitted from Exchange Parts are often deformed and should not be fitted but sent back faulty, the band needs to fit on the drum easy and be sprung open naturally so when closing around the drum they form a perfect shape, when released they should spring open from the drum.
Thanks for that info. So it would seem the band that’s in there has reached the end of its life most likely and needs to be replaced. Is this a somewhat straightforward procedure or fairly advanced?
Tilt the sweeps forward and the ROPS back. Pull the fuel tank and steering clutch covers. That will give you access to the brake bands. You should do both sides. If I was doing this, I'd pull the ROPS because there's always something else to work on and it helps to have the back plate out of the way. You might want to run her another 50 to 100 hours to see if you're gathering more material in your screens and filters. If you are, you'll be removing the T/C and transmission, and maybe the cross shaft outboard through the duocones. The brakes will become just another component along the way. If your transmission is coming apart, I'd get in there long before catestrophic failure. It will save you some time and money.
I noticed you suggested the brakes the first go round.
Just a quick update, I cleaned the magnet thoroughly and ended up buying a new screen for it because my other one was coming apart a bit on the top. Hauled to a new job this morning where I will run it about 50 hours and keep fingers crossed that no other debris keeps showing up. For anyone looking for a good way to clean the magnet, what worked for me after wiping off as much as I could from the outside was to use one of the magnet pickup tools you use to get dropped bolts and such and rub that on the inside and then keep wiping it off and repeating. Got everything I couldn’t from the i side
You’ve done an excellent job in cleaning that magnet up.Fair play. Good cleaning will come in very handy when those steering clutches come out to do the bands etc.I feel your steering controle valve will need to be stripped and cleaned too. Some heavy work ahead unfortunately,but perhaps you’ll get away lightly. Steering clutches and brake bands are t too heavy on the wallet,just labour intensive.I’d advise getting a good man to check your cross shafts etc out while you’re in there. TC travtors has depressing pictures of at least 2 of my D8’s he did this job on,but worth every penny.
Caterpillar Sproket Removal (also Komatsu) Just thought I would start a new thread on stuff I get up to, this will include sproket removal etc from D9G/H down through to D3, and Komatsus' from D30 to 155 as I dig out the pics. (May contain traces of nuts). HeavyEquipmentForums This link has been posted earlier up the thread, but for reference Nicky are some of those pictures in TC Tractor's thread here?
Yes,they will be most definitely
Hi again all, Back at it with my transmission unfortunately. Pulled my magnet and screen after loss of power and it’s filled with material. I’m pretty sure it’s clutch material but wanted to check with you all to confirm if it’s clutch or brake band material? Appreciate any input
If it lays flat clutch.
Definitely trans plate or steering clutch material.Looks like transmission to me
In all the years, I have never seen a perfect representation of a clutch disk, including the friction lines, on anything.
I’m assuming you mean that this is definitely clutch disk because of the friction lines on the large piece?
Indeed. Definitely clutch friction material.
So update and question, got a new screen because the other one was so clogged I broke it removing it. When I parked the tractor it wasn’t really moving I think because there was no fluid flow. Put new screen in and started it and it drives in all gears. First gear forward may be slipping a little but not sure if I’m just extra sensitive about it. My right brake has had issues for a while now and I’ve tightened it a few times to get it to work. I understand that’s it’s definitely clutch material that came apart. Considering how large some pieces were would it even drive if it was transmission clutches? Does this lean toward brake clutch? I did the transmission myself last time but don’t have time this go around, so I’m taking it to a mechanic. Is the brakes easier to get to in order to tell if it’s that before pulling the transmission out? Is there a way to tell off the material if it’s trans or brake clutch? Appreciate all of your insights
So I was talking to a friend and showed him this piece of clutch material, his thought was because this has a straight edge and not circular like on a trans clutch that it’s most likely brake lining. It made sense to me, wanted to know your thoughts? I know cab and fuel tank come off and can then open up the compartments under steering clutches. How big of a job is replacing the linings?
It is steering clutch brake linings. You’ve got a lot of labour ahead of you unfortunately. Yes,cab completely off,fuel tank off then a good jet wash. There will be significant cleaning required of all valves and the entire bevel casing. It’s a pain of a job. Tony Coates TC tractors will post all the pics and script you need for this job when he sees this post.
As for replacing the linings themselves,you need to ensure the condition of the drum.They can warp and appear to have eggshell cracks in them causing damage to the new linings. The linings themselves are rivited on. It’s very labour intensive,but if it’s simply that they’ve come apart,it may be a cheap fix. However,when you’re that deep,you need to check the clutch plates,springs etc are in tolerance.They are heavy rascals too. Once out,there are a number of seals and seal housings that require scrutiny in the top pinion area.Crown wheel and pinions need careful checking at this point also to avoid this happening in another few hundred hours time. It’s at this point,where your D8K will start to really hurt your moral.Physical pain will make itself present when your sat down in the bath tub with a cold beer in your hand.You may also notice that the sweat running down your cheeks is actually teardrops. On the upside,your wife will have long since stopped speaking to you as she’s noticed your bank account dwindle down to nothing.
Thanks for the brake down of it, including the personal deterioration . At least I know what’s in store ahead… What needs to be checked on crown wheel and pinion? Just for wear and tear or specific specs?
They need checking for lash and trueness. This is a job that I’ve allways paid a professional to do with me concentrating on the cleaning side of things and general labouring for him. It’s a skilled job requiring experience.
If you have a service manual, it will show you what’s needed