Hi everyone, I have the opportunity to do a work trade for a d3c series 2 lgp and a d6c wide track gear drive d3 serial: 5CJ00565 d6 serial: 6n15237 both of the machines start up and I operated the 6 for about 20 minutes, the gear drive takes some getting used to…. anyhow my questions are what are some things I should be double checking on both these machines, as some of you know I have an 8k that I didn’t check magnet filter on and had to do a transmission swap right away. for the d3 it seems to be in decent shape as far as running goes, my friend works on the farm and said they use it for cleaning up areas and making roads quite a bit. It has pyramid tracks that have holes in them and will need to be replaced pretty soon as you can see from pictures. the d6c seems to be decent except the blade is damaged and the cutting edge is folded back pretty good. My concern with the 6 is on both sides there is a rust hole above the final, not sure if this goes directly into the gears or if this is just a covering that I can weld a patch over and no problem. I will have a picture to post of it shortly. attached are a few pictures thanks everyone!
Here’s the rust holes that concern me
That final drive on the D6C will be full of dirt in the gears, and it's had oil pouring out of the hole, so that means it's running out of oil, and full of dirt, too. That final drive will need a major and very expensive overhaul. Patching the hole will be the cheapest part of the final drive overhaul. The blade is essentially destroyed by an imbecile of an operator, I've never seen anything like it. They must have been running into rocks in 3rd gear at full throttle. Run far away and run very fast from that D6C, it has been totally and utterly abused by people who should have never been given anything more mechanical than a shovel, to operate and look after. You don't show enough of the D3C to give a proper opinion, but it shows signs of abuse in operation, too. I'd treat that tractor as a risky buy, too, if it's owned and operated by the same people who ran the D6C.
Actually, those holes are in the tub, so they go thru to the steering clutch compartment. So if it has dry brakes and the bottom plug is out no big deal other than the frame may be rotten. If it has wet brakes this one will need a transmission soon. Unless you have a big income that you need tax deductions RUN FOREST RUN. Bad Bob
No D6C was ever fitted with dry steering clutches/brakes, they were always oil-immersed from the very first D6C. BOTH sides have holes in them, and one hole doesn't even show signs of oil?? That's an even greater concern. I can't even figure out how they were holed? Usually, the edges of track shoes and a loose/severely worn track, is what wears holes in the final drive/steering clutch case area - but those holes are too low, to be caused by track shoe wear? So - Yes, Bluox is correct - potentially serious damage to all bearings in the steering clutch compartments, bevel gear compartment, and transmission, as the oil is common to all three compartments. Back away, holding out a cross!
Thanks for the input guys. So sounds like it goes into the steering clutches so now there is possibly no oil and or dirt and water in the clutches. The dozer has been sitting for a long time and one of the guys from the farm just ran it for a few days not knowing much about anything and he is the one who broke the blade because I believe the gussets underneath broke off. I’m only familiar with my power shift 8k setup. Is the direct drive same situation where the oil is connected in all of them? If dirt did get into trans is it as damaging since there isn’t planetary gears and clutch packs? I hear what you’re saying about major issues I’m just trying to understand a little bit better. I wouldn’t be paying anything out of pocket for the machines except my time and some fuel to operate and clear about 7-10 acres which would go pretty quick with my equipment
Ahhh, sorry - I only just realised you said the D6C was gear drive (direct drive). Yes, the D6C direct drive transmission still uses common oil with the steering clutches and bevel gear compartment, same as all the Cat powershift tractors. Yes, the dirt ingress will have damaged pretty much all the bearings in the transmission and steering clutches, and bevel gear compartment. I would be surprised if you could clear 10 acres with the tractor as it is without it breaking down. What is worse, the transmission/bevel gear/steering clutch oil is pumped through the steering clutch control hydraulics system, which uses the pressurised oil to actuate circular pistons, to disengage the steering clutches. So now, the steering clutch control hydraulics are likely contaminated with dirt, too - meaning a total clean-out of the steering clutch hydraulic control system. The 6N15237 number you gave is not a D6C serial number prefix. That is a D3 S/No prefix. However, the highest 6N S/No, for a D3 with that prefix is 6N01225, according to my book. Neither is the 5CJ prefix, a D6C S/No prefix. The 5CJ S/No prefix is a D3C II LGP, built in Japan. If the D6C tractor was U.S. built, the direct drive transmission serial number prefix is either 74A or 99J, depending on the year it was manufactured, and which engine powers it (D333, D333C or 3306). There are a number of other countries of origin of the D6C, they were built in Japan, Australia, the U.K., and Brazil. Accordingly, the D6C D/D S/No prefixes are - JP = 41A, AU = 71A, U.K. = 82A, BR = 23U.
Weren't all D3's built in Japan? I have a little serial number booklet with some models but not sure where it is at the moment. It does look kind of rough. Don't sell yourself short accepting equipment that is either junk or needs expensive repairs. Figure out what you need to clear the 10 acres at a reasonable profit and don't over price the D3C if accepting it as partial payment. Based on the D6 do a pretty thorough inspection of the D3C. Check the undercarriage. If it needs it will cost approx. $10,000 maybe more. 3204's have more blow by because they only have 2 rings but still check it isn't excessive. Check the trans. and final drive dipsticks. It may have wet brakes, they were an option. If there are 2 square head bolts underneath to hold the brake bands up, you could loosen the jam nut and take the bolts out to check for water in the steering clutch/brake compartments. Beware they could be rusted so don't force them. To put them back in snug them and back off 1 1/2 turns and tighten the jam nuts. Some anti-sieze on them would be good if you had some. Wet brakes won't have these bolts. It should steer with light toe pressure and jerk you back in the seat a little if you change directions at about 3/4 throttle in 1st gear. This is just to test the trans. Normally it's best to lower RPM's when changing direction.The D6 is basically scrap so don't even consider it.
That's correct, and I didn't know that. I do know the 910, the 931 and the D3 share about 85% commonality of parts and components.
Totally irrelevant to the OP's problem but I ask...what in the world would cause holes to 'rust' through BOTH steering clutch housings on the D6C? and In Hawaii even? Would the volcanic nature of the soil do that? I've never seen that on any old dozers I've ever been around, and I live in the rust belt. Just a curious question.
I don't want to scare you, but there's no way in hell those machines are worth monkeying with. They appear to be some of the most neglected pieces of junk I've seen. I would never clear 7 to 10 acres for those things. I wouldn't clear half an acre for those things
The OP is in Hawaii which is all volcanic rock. It's like running on top of a disk grinder it will wear away metal steel that fast.
He also ran the 6 as it is for 20 minutes and the sky did not fall. Time being what it is, the OP may have it to clear those acres. I don't think he is using those pieces of iron to do that clearing, he has an 8. Figure on the scrap price for value and then price that job in your head accordingly. Patch those holes, flush and fill the fluids and roll the dice. If it starts and runs it may have enough life to be a push dozer at a fill site.
Thanks for all the input guys. I’ll do some more investigating on the d3 and see what kind of shape it’s in. is there a possibility of draining trans to see what kind of dirt and debris is in there or would the debris be stuck in the cavity by clutch packs and bevel? attached are the pics of serial numbers. I may have listed wrong number
Those ID plates are correct. The tractor S/No is the centre number on the top line. The D3C S/No is 5CJ00565, which makes it a 1991 model. There are asterisks back and front of the S/No to prevent fraudulent numbers being added. The D6C S/No appears to be 99J1993, this is a U.S. built, late 1973 year of build, the last tractor built in 1973 was 99J1996. It is fitted with the 3306 engine, and this engine has a separate engine number, and it should have a tag on the left rear of the engine block with a 3N engine serial number prefix. The direct drive transmission has a filter that you can inspect for dirt, I seem to recall it's mounted on the inside of the left chassis rail, near the front of the gearbox. The flywheel clutch also runs in oil, but the clutch has its own separate oil. The filler, breather and oil level gauge for the flywheel clutch are mounted on the RH forward side of the flywheel housing, below the bottom of the dash panel. The transmission pump is located high on the LH rear of the flywheel housing. The bearings in the transmission pump are fed with oil from the flywheel clutch oil pump. The transmission pump will be the first item to suffer severe wear due to dirt, because the oil filter is on the pressure side of the pump, and oil sucked up by the transmission pump is not filtered. The transmission/steering clutch oil level gauge is mounted on the top front of the steering clutch housing, under the seat, at the RH rear of the seat frame. Only the front bearings (double row taper roller bearings) of the three shafts in the transmission are pressure-fed by the transmission pump. The rear transmission bearings are flat roller bearings, and they are only splash fed. If the transmission oil is very low, the top splash fed bearings will probably be the first to suffer. Flat roller bearings will handle a lot of trash (metal particles and dirt) because they have more clearance than other bearings - but taper roller bearings have far less ability to cope with trash, because they are preloaded and have no roller to race clearance. The other bearings on the bevel gear/cross shaft are also taper roller bearings. When these wear, the wear will rapidly throw the bevel gear and pinion out of correct mesh, and you then risk bevel gear/transmission pinion failure. Also, if the bevel gear bearings fail, this makes the cross shaft drop, and this will chew out the piston ring seals (nylon or teflon seals) that seal the oil pressure in the steering clutch pistons, and the steering clutches will then not disengage, because the steering clutch hydraulic control oil is then simply being dumped.
John, I understand the abrasiveness of volcanic rock, but I'm struggling to understand what could have been providing the abrasion in the area where the holes have appeared. It's a considerable distance from the track chain and shoes. I guess if large volcanic rocks were being dragged through this area when the tractor was reversing, that may have provided the abrasion required. I've sighted more than a few final drive cases where severely worn track chains with bent shoes, wore holes in the top of the FD case, but these holes on the D6C are a whole new ball game to me.
yes those are a weird location.
The type of dirt that went in the hole would govern where most of it ended up. Heavy, coarse particles would tend to accumulate in the steering clutch case. Lighter particles will be carried by the oil to all areas. The steering clutch cases and transmission have multiple openings around the bottom so the oil can flow freely, and return to the oil pump pickup pipe, which sucks from the bottom of the steering clutch case at the front. There is a mesh suction screen in the suction line to the pump, this will prevent large particles from going through the pump, but fine dirt can easily go through it. Pull the suction screen and see what is in it. Here is a schematic of the oil lines in the D6C, the pressurised oil goes to the filter, then to the oil cooler (heat exchanger), and then to the steering clutch hydraulic control. From the steering clutch hydraulic control, the oil is then fed to the transmission bearings last.
Wow thank you for all the info!! I’m going to go up next week and dive into the d3 to see what I can find out. Told my friend about all the potential problems with the d6 and they are willing to let it go for whatever seems fair even if it is next to nothing. if I get the machine for $5k equivalent of work or less after checking more fluids and I’ve read on here about checking the sprockets movement and a few other things, is it a project that others would take on or would most not take it even if it was free?
Well, I think we've all taken on "projects" that have turned out to be a lot worse than we first judged. At $5K worth of work, I guess the tractor is worth picking up, because the bottom line is, it's the parts and components value of the tractor at that figure. But be prepared to do a lot of repair work, and pour a heap of money into the tractor. If you can do a lot of the labour yourself, that is a big saving - but remember, Cat parts are not cheap - even aftermarket parts - and a tractor this age is also going to have parts availability problems in some areas, as it's defined as an "obsolete" model and Cat support is declining for these older tractors. The main benefit is that multiple thousands of D6C's were built, so it's not like you'd be owning an orphan. The first thing to do, is not operate the tractor at all if possible, but concentrate on determining just how much dirt is in the transmission oiling system, and whether it's actually worth saving the tractor, or parting it out. Some decisions like this are borderline, and a lot of people have made the mistake of saving tractors that they would've been better off (financially) scrapping.
I wonder if those machines were run in salt water? That might better explain the bizarre holes and why there appears to be a lot of rust around them. The pads on the D3 have holes that look like they could be from (salt) water sitting in them. I don't think the D6 is worth anywhere near $5000. It might have the odd salvageable parts. It would likely cost far more than it would ever be worth to repair it. I'd much rather have the $5000 which is really low if that's what value you put on the clearing job. I'd guess at least double that to clear 7 to 10 acres. The customer would be laughing all the way to the bank if you took that D6 as payment. It's OK to say no on some jobs, especially if you feel the customer can't really afford it.
Thanks for the input. I am totally comfortable with not taking either of the machines as part of payment, I am however always interested to see what I can learn from these machines and I am pretty mechanically inclined and can’t afford new machines so if I’m able to get an older machine and put work into it, like my D8k, then I feel like it works out in the end. That being said, I do realize what you all are saying about not being worth it at a certain point. I know someone else over here who is a d6 enthusiast and does some incredible work on them and he said it’s not the first time he heard of holes like I found and that he would drain everything, fix the holes, clean filters and screens, and put it back to work. I’m gonna take him to look at the tractor this week and see if it’s really what he thinks from my description. He also has lots of scrap 6s with all kinds of spare parts around his shop. It’s hard to find equipment over here in general, especially if it’s in good shape and no matter what it’s never a good price. Here a couple pictures from my 8 where there was a leak on the left final. I think it’s a similar abrasion situation however the 6 has sat for quite a while
I don’t think they were run in salt water but probably not far from the ocean when sugarcane was all up and down the coast over here. For the terrain and vegetation where the site is located it’s about $2500 an acre to clear. So the $5000 was based on it only taking me a few days to clear 2 acres and it only costing me my time and some fuel IF there’s any potential in the machine. Initially they had offered for me to clear 12 acres in trade for both machines and I explained the issues on the d6 and I still need to dive further into the 3. My friend is the one running the operation and at the end of the day we both want what is fair for everyone
I think Devcon, Belzona and others make epoxies for high wear parts like pump impellers and casings. If your D6 expert thinks it's worth taking the D6 might be a good option to better help if it's an abrasion issue. Would be better than potentially having cracking issues if the cases are cast iron and you tried welding them.
Also I’m young and eager to build my business, it’s a lot easier for me to buy a machine that I can put money into along the way as I get more work rather than have to spend $100k upfront to get an ideal machine. some of you have seen my D8k post on the forum but others not, I bought the d8 and shortly after had to swap in a reman trans, done some other stuff along the way to it as well but it has provided an income for my family the past couple years and allowed me to clean my own land definitely already paid itself off and then some
I’ll see what he thinks, he’s just one opinion though and I know that many of you are also gurus so that’s why I’m trying to get multiple viewpoints. I appreciate all the time and information everyone provides. this forum has helped me through quite a few pickles!
Your D8 didn't have multiple holes in it. As far as fair, there is absolutely no way the 2 Cats are worth $30,000. No way! Friend or not he certainly wasn't considering what is fair for you. I'd be a little leery after him making that ridiculous offer. That said it CAN BE a very, very bad idea to do work for friends or relatives. They usually expect it to be as close to free as possible. If you do the work write up a contract the same as if it was a regular customer and include a clause for unforseen issues such as large boulders, excessive rock or abrasive soils. You don't want your D8 looking like the D6. Also keep in mind dozers aren't called money pits for nothing.
your right the d8 was in better shape in some ways. My friend doesn’t know anything about machines and so that’s where they started. Once I explained the issues they are willing to work out whatever is fair. He is in no way trying to swindle anything he literally has no idea about the machines. And also there’s nothing holding me to the machines I’m just trying to learn what the potential problems are and come out on the other side with a little more knowledge
I think as long as there are no expectations for you to accept the machines maybe a good arrangement could be made.
The steering clutch case and the final drive case are either steel plate or cast steel, they weld up just fine. Use some 7018 rod and just cut the hole back to full thickness metal, and stitch in a piece of steel plate, cut to suit the hole size. Or you could simply lay a piece of plate on top of the hole, and weld around the edges of it. I understand where you're coming from, on the availability and cost of good used tractors - Hawaii is like Australia, a big island (well, multiple islands in Hawaii's case) in the middle of a huge ocean - and it's pay all the way in both locations, for the limited quantity and quality of equipment that's available. It's not the continental U.S., where the choice is huge, and you don't have to go far, to find exactly what you want - in good condition. The first things to do with the D6 is check the mesh strainer and the transmission filter. Then drain the transmission oil and wash out the transmission and steering clutch cases with diesel. The transmission pump pressure needs to be checked for output pressure, to see if it's still within specs, or if it's been badly worn by the dirt and is not producing adequate pressure. At least, the gear drive drivetrain will cope with dirt better than a powershift transmission, as there's no transmission spools, clutch packs or planetary gears with needle roller bearings in the direct drive transmission, that don't cope too well with high levels of dirt.
I wasn't sure if the cases were cast iron but cast steel or plain steel does weld fine. Although it would very unusual I suppose working in very abrasive material you could put some hardfacing or just normal weld on the cases where they wear. A checker board pattern would hold material and stop other material from wearing the cases.
Thanks for the info, I am gonna go up there on Tuesday and dive further into both machines to see what I can figure out. I’ll post some pictures of my findings in the strainers filters and oils
Alright here’s some updates… For the D3c: 1) definitely needs a complete new undercarriage, pads have holes and the sprockets are sharp. 2) I’ve read on here that the steering should only require light toe pressure to steer, hasn’t been used for a while so the linkages seem a bit sticky but it doesn’t really steer hard until the pedal gets to the end of its swing pretty much 3) transmission seems to shift very good and the oil in trans and bevel case were both in good condition and at correct levels. 4) regarding the dry vs wet clutches, I read about if it had a plug on the side then it is wet clutches, is the picture of the plug attached what is being referenced so it is wet? 5) engine runs good, no weird noises and it has blow by but what I understand is that’s normal on this engine. The head isn’t painted so I’m guessing someone redid it at some point along the way, hour meter reads 2013 hours any thoughts or other checks? d6c: 1) pulled the trans screen and filter, the screen had A LOT of dirt in it. Picture attached. And the oil was total milk due to all the water. stuck my fingers into the holes in frame and there is a good amount of sludge around the holes 2) the right side final pinion seal is worn so the final is filled with milky oil that overflows and the left side final was bone dry from what appeared to be a loose plug on the bottom. Stuck my fingers inside the bottom drain plug and pulled out what appeared to be some chunks of carbon buildup 3) tried moving the sprockets but couldn’t get any wiggle out of them, but the tracks are over tightened so not sure if that is why 4) the left side track is toed out a bit, I read on here to look for that but can’t remember the cause or diagnosis. Thoughts? At the moment my thought is to clean everything out, fill up all the oils, run the machine for a couple days, change the oils again, run the machine, then do it all over again. I made a potential deal to clear 6 acres (~$15,000) worth of work in exchange for the 2 machines and a $10,000 trailer. Thoughts?
I take it that the D3 is pedal steer. I think you have it figured out OK. Loosen the linkages and adjust as needed. Do you know where the steering brake adjustment is? I don't know if it is wet or not. The serial number would likely reveal one way or the other. On the D6 the water in the oils seems to be common in Hawaii. The empty final might just leak any oil out that you put in. The leaking pinion seal on the right side is pretty common. I've had dozers of that era and just ran them. When they stop turning, you have to fix them anyway, or not. What I remember about toe out was dead axle and swing frame brace problems. That may be part of the problem with no oil in the final drive as well. Your deal sounds like what a lot of people over here did years ago. Trade things for labor and leave the cash in you pocket. Them throwing in a trailer kind of sweetens things up. What happens though if one or both of the machines break down before your clearing job is done?
You haven't shown the condition of the track chain rails or rollers. Are the roller flanges hitting the pin bosses? Sharp sprockets only shows the track bushings are worn. This tractor should have sealed and lubricated track chains - they're identified by displaying a sizeable hole drilled in the end of the track pin, and in the centre of that hole there's a plastic plug. The brakes may simply require adjustment, or the linkages are binding due to wear and dirt. Disconnect the linkages at the steering clutch covers and try the pedal action again to see if they move freely. If they do, adjust the brakes. If they don't move freely, track down where they're binding exactly. Best news we've heard so far. That's the way they should be. The D3C has wet clutches, the D3's had wet clutches from the earliest D3B's, the design changed from dry clutches to wet clutches around 1980. You could get a conversion kit to change from dry to wet clutches for the early D3B's and 931B's, it was called a Custom Shop Modification. Here is the manual for the dry-to-wet clutch conversion, showing the earliest D3B and 931B serial numbers with dry clutches, that could be converted to wet clutches. Any serial numbers after the numbers shown on the cover of this manual are wet clutches from the factory. The plug you photographed is an access plug, possibly to assist in removal of pins from the brake mechanism or to give access to steering clutch pack bolts. Sounds good. The blowby is normal, the Cat 3204 engine is a "low friction" design and uses only 2 rings on the pistons. You can buy 3 ring pistons for them, and the turbocharged 3204's used 3 ring pistons. We need to see photos of the track chains, the track bushings, and the track rollers to determine track condition. Also, whether the tracks are SALT (Sealed and Lubricated Track) or older style dry tracks. If the undercarriage has been reconditioned previously, someone may have fitted dry chains to try and save money. The cooling system and radiator condition is important. If the cylinder head has been replaced, the engine has possibly been overheating.
I was typing when Ozdozer posted. I don't think wet brakes were ever a standard feature. Same with the 3F 3R transmission. Great idea to check linkage is free. I'm pretty sure the square plug in the OP's picture is for getting at the bolts that hold the steering clutch and brake assemblies on. You can stick a socket in the hole from the outside. I have a 1986 931B and it has dry brakes. It's easy to check though. Easiest way to check if wet or dry is look underneath the brake housings. Dry brakes will have a steel ring protecting a square head bolt with a jam nut. This is the brake band support. Wet brakes don't have these bolts. Wet brakes were optional so maybe a build sheet would show if they were added. I don't think there was a specific serial prefix for wet brakes. I think adjusting the brakes is similar but much more critical not to have them too tight on wet brakes because they will wear into the drums. With dry brakes the easiest way to adjust them is to remove the linkage rod at the back of the machine that goes to the big cam on top of the clutch compartment. There should be a simple to remove hair pin. Then tighten the brake adjusters under the seat (9/16" socket) until snug. Then shorten that rod as much as possible that you can still get the pin in. The brake pedal should be all the way up with little freeway. Then loosen the brake adjuster approx. 1/ 1/2 turns to get about a half pedal of freeplay. Loosening at the brake bands guarantees the freeplay is at the brakes and not in the linkage. You could also snug the bottom brake band supports with the square head bolts when snugging the brake bands. Make sure to loosen them off about 1 1/2 turns before loosening the brake adjusters when you're setting the freeplay. Beware they could be rusted and not want to turn. If they turn freely you can also take them out to check for water in the clutch/brake housings. Before anyone wants to jump on me, this is how Bob/Ont explained an easier way to adjust brakes than measuring all the linkages like the manual states. When adjusted properly machine should coast on a slight downhill or if you drive in 2nd gear and shift to neutral should coast for several feet before stopping. This also depends somewhat on if the steering clutches are working properly. Shouldn't have to stand on the brake pedals to turn.
The level of dirt is of concern, and the amount of metal on the magnets shows some major wear levels in transmission/steering clutch/bevel gear departments. The steering clutches will need to be pulled out to replace the final drive pinion seals. Both will need replacing. Probably not a bad idea to do that anyway, then you can clean out the steering clutches and replace the hydraulic steering control piston rings and examine the bevel gear bearings for wear. The D6C had wet steering clutches from the very first D6C produced in May 1963, the D6C tractor was a whole new "clean sheet" design. A bone dry final drive means the entire final drive is likely to be totally destroyed. You can shine a flashlight into the final drive drain hole and filler hole, and see what the level of metal particles looks like. A borescope inspection camera is also a useful tool to get a look in there. They're not expensive today, but buy or borrow one with good camera resolution and a decent size screen. You will not be able to get any sprocket bearing movement with a really tight track. Loosen the track and insert a crowbar between the FD housing and sprocket, and see if there's any sizeable level of movement. Track toe-out is caused by - (A) a bent diagonal track frame brace - (B) worn sprocket outer hub bushing/bearing, or worn diagonal brace bearings, or both - (C) a bent track frame. Most likely cause is (B). That's the cheapest option as compared to pulling a lot of components apart. That sounds like a fair and reasonable deal.
Dave, are you sure your 931B is a 1986 model? What is the serial number? My information tells me all 931B's after the serial numbers listed on the Custom Shop Modification manual were wet clutches. The style of transmission in a D3 or 931 is related to the tractor S/No. Early machines had the 3F/1R transmission, then the 3F/3R transmission was offered - but the tractors fitted with the 3F/3R transmission carried a different S/No prefix to the tractors with the 3F/1R transmission. I don't think it's a practical possibility to do a conversion from a 3F/1R transmission to a 3F/3R transmission, the design changes were substantial - but I guess someone has probably done it, somewhere.
Thanks for all the info! I will get some pictures of the chains and rollers and get them posted up here. Once we finalize a deal I will start working on the brakes and follow yours and welder Dave’s processes to get them tuned up. Thanks for clarifying about the wet clutches and the engine. From what I was told they took the radiator into the radiator shop in town a few years back and had it cleaned up. Not sure exactly what was done or what was happening, the current farm employees don’t know specifics
I’m not familiar with the removal of steering clutches, I opened them up on my D8k but didn’t remove anything. Is this considered a major repair or is it a relatively simple procedure? What in particular am I looking for inside the final to tell if it’s totally destroyed? Any thoughts on cost of doing the finals on this dozer? I will loosen the tracks and recheck sprockets. If the toe out is cause by the outer bearing being shot, does the entire track frame need to come off to fix or can that be done with only splitting the track? Also what are consequences of continuing to run it if the bearing is shot?
My machine is 25Y 01916. I have a brochure as well as an update sheet I got at the Cat dealer. Later "Improved 931B's" had a higher lift height but slightly less breakout force. 25Y serial is 3F 1R trans. and standard gauge but nothing to do with the brakes. Cat says if you're not doing lots of backing up or steep grades like digging basements the 3F 1R is a less expensive option that will give you the same reliability as the 3F 3R trans. They use the same torque converter. The backhoe was also improved. Biggest difference is it went from a rack and pinion swing to a rotary cylinder swing. There's another Cat publication I've never seen comparing the D3B/931B backhoe to the John Deere 450C backhoe. I'll see if I can find that update sheet and an early 931B brochure.
It is regarded as a fairly major repair, but it's not complex or rocket science. It requires the fuel tank and seat frame to be removed to access the top of the steering clutch case. The steering clutch covers are unbolted and removed and the steering clutches are unbolted from the drive/driven flanges each side, and lifted out, using the brake bands. The final drive pinion is removed by unbolting the bearing cage from the FD side of the steering clutch housing, prising the cage/shaft/drive flange inwards into the steering clutch compartment. The outer pinion bearing can only be accessed by removal of the FD case. Sizeable pieces of metal, pieces of bearings (chunks of rollers) and chrome-coloured metal debris that has come from bearing races breaking up. You will likely find chunks of gear teeth and curved pieces of the face of gear teeth, these are not as important as finding pieces of bearings. There's always chunks of gear teeth breaking away in final drives, especially as they get older. They will run for a long time with chunks out of gear teeth, but they won't run for long with bearings breaking up. The FD gears run on mostly flat roller bearings, but the sprocket shaft runs on big taper roller bearings, inner and outer. Flat roller bearings will cope with metal trash, roller bearings not so much, as they have preload on them, whereas flat roller bearings have operating clearance, and that clearance can be large, and the roller bearing will still perform O.K. You can continue to run with toe-out, plenty of tractors around with that problem. It increases track wear, as the tracks are not running true - not a lot different to toe-out on the steering of your pickup. The outer sprocket hub bearing can probably be repaired without track removal, but track removal makes access easier. The track needs to be fully slackened and the cap over the outer hub unbolted and removed and the inner diagonal brace cap removed as well - to allow for the tractor to be jacked up and the outer section of the track frame dropped enough so the hub can be pulled off. The outer hub has a bronze bushing that oscillates on the hub that contains the outer sprocket bearing, and which hub is pressed onto a keyed taper on the dead axle. If the hub that the bronze bushing oscillates on is badly worn, it will need to be replaced, or built up and machined back to size. You can remove the hub that contains the outer bearing by undoing the big central nut on the dead axle and by unscrewing the sprocket bearing adjusting nut. This pushes the hub off - but to re-install it, it needs to be pressed back on. The inner bearings on the diagonal brace are simple hardened steel bearings that fit into the brace like a big-end bearing - but they are dowelled in the brace and the cap to prevent them turning and to keep the grease holes aligned.
Dave, my 931B is also a 25Y prefix - 25Y1213, which according to my book, makes it a 1980 year of build. Seems like production of the 25Y models fell away badly in the early 1980's, they didn't produce a big number of them in that period and it took until 1987 for Cat to produce the last 25Y model, 25Y1976. My machine has no hoe, but it has a 4 in 1 bucket. I wonder why the Cat Custom Shop Modification booklet states the S/No's as 25Y1 to 25Y1726 as the machines capable of being converted to wet clutches? Perhaps only these tractors needed this special modification, all others from then on, could perhaps be converted without the specified modifications?
My machine is a little weird. It has a factory hoe with the larger piston pump and a 4 in 1 bucket but only the 3F 1R trans. I don't have my little serial number booklet handy but there were around 2000 25Y machines and about the same for the 3F 3R machines. I think they were 29Y but not positive. I'll have to look for the info I have.
Wow thanks for all the info! From what I’ve heard from people they say that having the seal into the final worn is somewhat normal on old tractors and they recommended to just run it like that until you have to do the finals. Would you agree with this? It seems there are a lot more pressing issues to address for now… The only thought I had was whether or not I should drain the milky oil out of the left final because there’s probably some dirt in there as well and fill it back up and then watch trans level since it will refill it above what I can add. Attached is a picture of the only metal I found in final when I removed the plug, there’s probably some more stuff in there but this is what I could get out with my fingers. There was also some black compressed chunks that appeared to be carbon build up, kind of seemed like dirt but when I broke them in half they were black and porous on the inside I will run it with the toe out for now as well until I get the system cleaned and get the rest of the things addressed if that’s not a pressing issue. Unless there’s a crack in the final casing somewhere is there a seal or somewhere else the oil could have drained from while it was sitting for the past year? The drain plug was loose when I opened it and my thought was it could have leaked from there?
Yes, you can run the machine with a pinion seal gone, but you will have a regular lowering of transmission oil and a regular increase in FD oil, so that's an additional cost, topping up the transmission oil. If the FD overfills, it will come out the FD breathers, which are located on top of the steering clutch case. There's a small steel tube that runs between the breather and the top of the FD. Yes, by all means, drain out milky oil - it contains water, which will only cause corrosion if left in there. Water also depletes oil additives as it binds to them. The metal pieces have no size relativity, as you haven't put them against a ruler or tape - but they appear to be chunks of bearing race. Not a good sign. The black and porous chunks may be remnants of a rubber toric ring (which supports the metal face seals on the sprocket), if the metal face seal has been destroyed. You can run with toe-out, but it indicates problems that must be addressed eventually. Any severe wear where there is a vastly increased clearance, only increases potential damage from the hammering action of constant movement of the worn mating parts. The oil may have leaked out of the loose drain plug, or it may have come out via damaged metal-to-metal face seals, which are located each side of the sprocket.
I found some brochures and a Product training bulletin, 931B update (not dated but guessing around 1985 maybe earlier). There is a 931B brochure from 1982 and 931C series II from 1990 which I think was the last model of 931 before Cat went to the 935 I think. I also have brochures for the early backhoes and later backhoes. Edit. 931 backhoe and early 931B backhoe. Updates were: Longer lift arms Extended track length (36 to 37 link) Improved fixed pivot and side shift backhoes Improved 3204 engine (62 to 65 HP, redesigned bearings increasing load capacity, heavier engine block and vertically mounted oil filter with external bypass valve prevents contamination of the oil supply during bypass) Corrosion resistant dry steering clutches and brakes (a corrosion inhibitor was added producing a vapor which prevents corrosion and then pressure tested) Also longer lift arms increased dump clearance from 96.9" to 103" and reach from 31"to 33". Both a 6% increase. Digging depth was also increased from 4.7" to 6.4". Tilt cylinder rods and links were lengthened to accommodate the longer lift arms and provided a greater roll back angle at carry height from 45.5 deg's. to 51.2 deg's. Breakout force was reduced slightly from 14,725lbs to 14,275lbs. The Cat corner guard system (bucket teeth straddling the side plates) was optional. Sorry for the sideways pics. Not sure why the 2 were sideways.
Yes, I came across the smaller diameter tilt cylinders thing when I was researching the repair on one of my tilt cylinders - which I've just fully reconditioned with all new seals and a new shaft. I think mine is 3" diameter, the improved version has 3.25" diameter cylinders? Also at 25Y1897, Cat changed the final drive bull gear and pinion to finer teeth. The older bull gear has 50 teeth, the newer version is 56 teeth. I haven't found the tooth numbers for the pinion.
I found another sheet listing the Cat track loaders but the 2nd page is missing. The 935B started in 87 and 935C series II ended in 1993. The 931C was upped to 70 HP, the 935B is 75 HP, the 935C was 78 HP and the 935C series II was 80 HP. It appears after 1993 is when they went to the hydrostatic loaders.
Yes, I believe the tilt cylinders were bigger on later models but nothing is listed concerning the final drive gears other than the parts book as far as I know. That's why the serial number is so important when ordering parts. My serial number seems to be weird because even the Cat dealer can't tell me for sure which oil filter I require. I know it's the later version like on the 931C but I always take the number off the old one. Just last summer I had something really bizarre happen. The fuel filter developed a pin hole leak in the side and was spraying diesel everywhere. Might have been better it was toward the firewall but have never seen or heard of a fuel fuel doing that. I'll take a pic. of the filter the next time I go out to my property. There is a very tiny nick in the paint on it. You'd never know it would leak like that. I took my tilt cylinders in because they leaked out the gland a little too much. I think the shop took advantage and hosed me. They said they had .010" bend and the chrome was bad, etc. $1750.00cad. to have them done! Dave
Ouch! I bought NOS seal kits for mine, at around AU$50 a pop (one came from an eBay seller in the U.S., and one came from a Cat dealer in Eastern Australia. This dealer runs a NOS parts dept). The worst part was - when I was looking for another part for something else in my NOS parts stash, I found a seal kit for the 931B tilt cylinder!! That was AFTER I'd already purchased the other 2 seal kits! I bought two lengths of chromed hydraulic shaft new, for AU$200 for the pair. The most expensive part of the deal - I paid a machinist buddy AU$400 to cut the end off the old shaft, machine up the new shaft to take the piston and nut, and to weld on the old pin end. I found aftermarket pivot pin grease seals for AU$11 each - and I did all the disassembly, cleaning and re-assembly myself! All-up cost of the tilt cylinder reconditioning, not counting my labour - less than AU$500! The other tilt cylinder is still working O.K., but I have it scheduled for a full recondition within the near future. First off, I have to sort out the piston and oil pan problems with the engine. I've already picked up a good used cast iron oil pan for AU$500 (ouch! - but much better than the new Cat price!) I still don't have the transmission operational, although I was told it was working when it was parked up. I've seen quite a number of forum posters complaining that their 931 transmission had stopped working after being parked up for a time - but nowhere have I found anyone who said what caused the problem! I suspect the transmission oil pump in my 931B has lost its prime, or maybe there's something else letting the pressure go - I just haven't had a chance to work on it properly for some time, but I have to get back to it soon.
The shop that did my engine found a used cast iron oil pan and it was $350cad. by the time it got here. A new stamped oil pan was $800cad. Like I mentioned they had to cut some bolts shorter. They also said my oil pick up tube/strainer was cracked so replaced it.
Hi guys, First I have a question about washing all the cases out. You mentioned using diesel to wash everything, is there any where I can use to diesel to clean things? Steering clutch area, finals? Attached are pictures of the sprockets, rollers, idlers, and links on the D3c As always, thanks for your time!
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that's funny, "Fern Gully" won! that had to have been around salt. Anything that had oil in it can be rinsed with diesel. You don't need to waste the diesel either. Put a bucket of clean fuel with a weight on top of the cab, siphon into the compartment with a hose while it drains into a clean bucket. Let that bucket sit until it settles and siphon it back into the other bucket, then up on top of the cab to repeat. If you have several buckets settling, and rinsing the dregs into a final bucket, you can do the whole thing and waste very little fuel at the end. Keep rinsing until nothing settles out anymore.
You can use diesel to wash out virtually any compartment on a tractor, it's not going to harm anything. Wow, my corrosion problems are nothing as compared to yours! Those track chains are corroded like they've been in the sea for 20 years! You're going to have some fun trying to remove any bolts from any area on those track frames! The undercarriage is in reasonable shape, wear-wise, but the extreme corrosion on the outside of those track bushings has seriously reduced their lifespan. Has the tractor been lying in a deep pool of water? You need to find some kind of protective spray to try and keep that corrosion down, it will end up causing a lot of weakening of components by thinning the metal down everywhere. That broken track recoil spring really needs replacing, but you can work it, as it is. The only tractor I've seen worse than that D3C is a D5 that was left on the West Island of Cocos-Keeling Islands. The contractor built a new jetty, and they shipped in a D5 to do the earthworks - and just abandoned the tractor when they finished, because the cost of shipping it back to Australia was exorbitant. The corrosion on that tractor was incredible - constant humidity, right alongside the ocean, constant wind carrying salt air.
Thanks for the tip. I’ll definitely try this method out
Ok sounds like I’ll use the tractor as is for now and wait to replace the undercarriage until it doesn’t have life left. It’s mainly going to be used on my ranch to clean up after the bigger machines. Would you recommend just spraying everything with a rust killer for now and as the big chunks fall off from use treat it again as I go?
Sprockets are pretty bad among other things. I'm not sure if you'll get your monies worth before you'll need to do some expensive undercarriage replacement. Wouldn't be surprised if a bunch of pins are seized. Looks like the machine(s) have been sitting for a long time.
If you were replacing undercarriage parts for farm use, would you concentrate on sprockets and chains or do all the rollers need to be replaced as well?
I'd get it operational and run it for a few hours, and then spray the rust killer on it. That way you're not wasting rust killer on big chunks of corrosion, that are going to fall off, anyway.
Undercarriage components operate as a group of matching components, that theoretically, should all wear out together at approximately the same rate of wear. In the real world, this doesn't actually happen, but the components do wear to match each other in use. If you replace just one component, or a couple of components, with new components, you then end up with mismatched components, which means you don't get the full expected life from the new components. So ... if you install new chains with worn rollers, the rounded wear pattern in the old rollers means this wear pattern will round off the track rails, so you shorten the track chain life. In addition, worn roller flanges will start to hit the pin bosses on the track chains, before the track chain is well worn, thus meaning the track chain life is shortened again. If the roller flanges start hitting the pin bosses, your tracks are scrap within a very short time, because the constant impact of the roller flanges on the pin bosses, loosens the pins and makes them fall out. The sprockets as they are, are quite serviceable. Run them until the points on the teeth disappear, you'll know you can't get any more life out of them when the sprockets can't drive the track, and they spin inside the track chain! I've worn tracks out so bad, the sprockets just had rounded bumps where the teeth had been - and when I went to climb onto a trailer, the tractor struggled to climb the ramps, because the sprockets were spinning inside the chains!
You have SALT chains installed and the corrosion is a minor issue at this point. It appears that chains, rollers and idlers were replaced together in the past but the sprockets were left to run. That will wear the front outsides of the bushings faster than if the sprockets had been replaced at the same time. Judging from your prior descriptions of the tractor I would not even consider changing anything at this point as you have a job to do which will take off the corrosion and you don't know what other kinds of issues with show up with the tractor as you do the current job. Sprockets have issues but unless the tracks start to jump when turning the machine in reverse, it will work just fine for now. That occurrence may be more pronounced and happen soon with that broken recoil spring. The spring is dead so likely won't be much problem to replace with a used one. The big problem will be in finding a used one. Probably not very likely on the big island.
I thought he was doing the job with his D8. He could play around a bit with the D3 though and might discover it's good and bad points.
I'd pressure wash whatever will come off, then soak with diesel. Diesel has enough wax to do a decent job of rust prevention, or you can set a metal bucket of diesel in a warm truck cab and drop in old candles to fortify the wax content.
Ok I’ll run it as is! Best news I’ve heard all day since I got a quote for a new undercarriage from Trek including the spring for $14,000…. I know there’s a lot of downsides to going aftermarket but I figured since this is going to be just for around my ranch it won’t get that much hours on it every year. Wow that sounds like some major undercarriage wear! Hard to spin a track when your sprocket is round as a golf ball!
Thanks for the reply, I will run it for now and see if there’s any other hiccups that pop up along the way. Between this and the d6 a new undercarriage is least of my worries at this point in time
I have my D8 as a backup but I’m going to work on the d6 in place and try to get as much of the clearing I can done with that and my 320b excavator, that way I can still do other jobs with my d8 for now and still pay the bills. they gave me almost 6 months to get the clearing done so it gives me way more than enough time to work on the machine, clear, then work on it some more and so on
Great tip. I’ll pressure wash and run the machine for a little bit to knock off the chunks then spray it down with diesel. Would you spray rust killer on it first before spraying with diesel?
Even from Trek the cost seems a little high but maybe shipping to Hawaii adds quite a bit to the cost. You need to see if it has 36 or 37 link tracks. If you are taking the D6 in trade you probably want to clean it up and see what all is wrong with it. If you plan to scrap it won't matter too much.
Im pretty sure that was without freight too. Because the guy from the local shop said he didn’t know how many pallets it would be packaged on so that would depend on freight cost
Did he break down the cost and were they SALT rails? I got SALT rails because they were only a couple hundred $$ more per side. If it was a local shop should have been the price from their location so included shipping.
It’s a local aftermarket shop not a cat dealer. He just gave me the price after he called for price. He’s going to send me a breakdown on Monday of all the individual prices for the parts. Also waiting on a quote from the cat dealer, and a price from someone else who is a trek distributor so we will see what they come in at
His prices should include shipping to his location. Wouldn't be a bad idea to get quotes from other aftermarket and Cat for comparison.
Hi everyone, it’s been a while but I figured I would come an update everything. D3C: brought it home and I’ve been using it mostly around my property to clean up and spread material. For the most part it runs good, the left track tensioner leaks a bit so I gotta stay on the grease so it doesn’t get too loose. The left side brake also needs to be adjusted I think because to engage it I have to pull the lever almost all the way. Blew a handful of hydraulic lines, none were that bad except for the hard lines under the transmission so I cleaned the belly out while I was in there. D6c: if you remember the left side final was bone dry when I first looked at it, I poured a bucket of diesel in it to see if it was leaking and all the diesel came out of it in a hurry so the seals are toasted, makes sense with the toe out on that side and being dry. I have 2 people who are interested in it so I may just sell it instead of pouring money into it
Thanks for the update it's always to to get the latest on past threads that go silent. I hope you get to satisfactory conclusions on both pieces