We have had a weeping final drive seals on both sides for some time, so decided to replace them one at a time. Took the housing apart to inspect things inside & so far all bearings/races look good. The #5S6531 Holder has wear from where the track pivots at the back & the large brass pivot bearing is shot too. Have ordered both the new Holder & the Support #5M6636, as they were reasonable priced. I have never been able to get grease in that back pivot since owning it. If there are any words of wisdom to send along, I would appreciate it. I have a young mechanic helping me with the work as a fill in job, so it will take a while to complete. We are both feeling our way, but think we will get there ok. He does a lot of work on the newer Cat equipment. Once we get this side done, we will likely tackle the other side if the cost does not get too far out of hand. Stay tuned........
Its a little hard to see but the race for the inner bearing on the sprocket shaft has a couple of flakes out of it. New one on the way. All bearing look good.
I have a D6D needing a left inner seal, so i feel your pain. Its sitting waiting to be torn down. Never been that deep so I'm new to it. As for that back pivot you are talking about I call it the wishbone, and it has a 2 piece bushing in it. If it wont take grease its usually because that bushing has cracked or broken and spun a little bit. You can see it in the first pic to the left, its got grooves cut in for the grease. Keep them greased and make sure the bolts that hold the cap on are correct length, and always tight. I have seen guys throw whatever in there and one or two back off or are too short. What ton puller did you have to use to pull that sprocket off the hub?
Here we are with the RH side getting ready to go back together again, with all parts having arrived as far as I know. The young man who is doing the rebuild is a good mechanic but has never done a final drive on a tractor like this before. I wanted to ask if anyone has any suggestions on any special cleaning precautions/procedures for everything that has been opened up? Also, once back together I wonder if it is a practice to do a flush with some cheaper oil for a couple of hours running or just clean it well & use the TO4 product with not flushing? Plan to go ahead & do the other side once this side is done, that way we call Cat in just once to press the sprockets back on.
Clean with a solvent gun, assemble, fill and go to work. There is an advantage in working on both sides at once that way you can swap gears side to side to reverse the wear if needed. At least that's what I always did if I had to work on both sides. Nice tractor by the way
Here we are getting into the LH side, which we decided to tackle while we at it & found some flaking off on one spot only on the bull gear. Everything else is pristine on it the bull gear. I am on the fence as to whether or not to change it out or leave it? This machine works maybe 200 hrs max annually. What are the thoughts on changing it vs leaving it & putting it back together as is? The smaller intermediate gear that is driven off of the top pinion gear has more damage to it, presumable from some past failure. I will post pictures of that one as well. There was no evidence of any pieces or chips in the gear case, so likely the damage was cause from something in the past.
Here is that intermediate gear driven off of the top pinion gear, which show some damage. It is part # 1P-1898 in the parts book for the whole assembly. The smaller gear in that assembly is fine, no damage to that one at all. The larger one of the two in these pictures has been ordered & is 5 days out. Again, nothing in the gear case to reflect any recent problems, it was clean inside, but I think changing this one out is the best option. Does anyone have a breakdown of how the two gears come apart? If we have it right the larger of the two gears is # 2P-3422 & the smaller one is 2P-3423.
Can you swap sides with those gears?
Your gear is one piece,the other two part numbers are a set to make one like yours. Have you checked classic parts yet? Bob
If yours is two piece they a coarse splined together with retaining ring in the larger gear.
As a fair warning the spalled spots with lifted metal is where these will fail from stress cracking, you can probably gat away with the gears for awhile but you will end up back in those finals in a short time if left in there. Won't be as easy or metal free next time.
I wonder if these pictures help identify it as either a one piece gear assembly (#1P-1898) or separate assemblies splined together as mentioned by OM?
I did not check Cat Classic yet. Makes me a little nervous about putting classic parts in there, even though they are going to be much cheaper........ Did not swap sides for the gears as we decided to go into the LH side after the RH was going back together.
It is a one piece. If you are buying cat parts ask for classic part prices..Classic parts are more than adequate for this use. Bob
2P3422 gear=213-8415,2P3423 pinion=216-3553,ring 2P3421. Bob
Ok, we revised the original order from genuine cat & decided to go with Cat Classic. Ordered the gear, pinion & ring. Also, we may regret this, but decided to reuse the bull gear & to put in back on the opp side of the machine. We did some work in the bevel gear compartment about 2 or three years ago & the mechanic saw the same markings on the bull gear through the pinion shaft hole when the pinion was out & said it looked the same. Note, when swapped to the other side it will be on the reverse side when engaging.
I'd be concerned about using Cat Classic/China knock off in that high stress application. I'd even consider good used original over the China stuff. Swapping sides with the bull gear is a common practice.
So how much classic parts have you used? Bob
I really hope that this is a decision that I do not come to regret, but the savings over using OEM was so vast I decided to go this way, given the fact that this is a 200hr/year machine. I did check on used & was not able to come up with anything, or would have considered that as a viable option. When we did the bevel gear compartment over a couple of years ago, we located a good used upper drive pinion for the one side that was used & it worked out well so far.
Metalman, I've been doing this for 50 years and have used classic parts for 20 years,have not had problems.My son worked for Cat for 10 years then a contractor with 150+ pieces of Cat equip. he uses classic parts. Do you think Cat would sell you junk parts with the same warranty as their oem parts? Most part guys don"t push them because they get a commission. Bob
Thanks for the reassurance Bluox. As with may subjects, there are a wide array of opinions on this subject & I understand that. Different people have different experiences & try to reflect what has worked best for them & they in turn pass that information along to help others. I appreciate the comments from both sides.
for all the time and $$ you are spending now, how much more to get new replacement bull gear and related parts? and if it did let loose, how much will you chew up in new components and more older parts once you get bigger chunks of metal floating around, bite the bullet and get the new parts and sleep well at night...I think most would go that route with all you have done already..
Here we are with the sprockets going back on today. I was not there..........just curious, is the 8M9010 Sleeve just a piece of pipe, or is there some fancy machining inside of it? The mechanic said the Cat guy was not there long doing it.
Well, we got things put back together in the D6C Finals & finally got around to picking the machine up a few days ago from the repair place. Today was my first time to try it out & so far all looks ok......no leaks from the finals on either side. I worked the dozer hard for about 5 hrs leveling some fill piles that were alongside one side of the farm driveway that we worked on widening last summer. With the driveway frozen it worked ok to just push 1/2 of the fill across the laneway then knock it down to meet the new raised elevation to blend things in. Some places on the pile had a frozen crust about 15" think on the piles, so it took some doing to crunch them down. Not so cold here today, so good for working! It has been mighty cold here for the last 10 days or so.
Have been using the D6C for pushing the snow piles back here in Ontario & so far the final drive repairs are holding. Hope it continues!
Purdy bucket on that ol machine!!
The classic parts are not as good as they used to be. Ive bought the classic precups and they snap off in the head before you get them torqued down. You can get away with classic on a lot of things, but I wont use them if they need a lot of torque, or are used in high torque operations. Just my experience and Ive been doing this crap for 30+ years.
I rebuilt a final in my 6D three years ago, put all classic gears in it except the pinion was cat. it ran exactly 100 hours and the intermediate gear flaked off wrecking it and the bottom big ring gear. there was no warranty on any of this. I put in new cat gears. do not buy cat "classic" anything.
There is a wide variety of options on this subject, that's for sure! I guess some have good luck with the Cat classic & others not so lucky. If a failure like Oldirt had happen occurs, that would leave a bad taste!
Pulled the bottom drain plugs on both sides of the finals today after logging about 30 hrs on the machine, some of it heavy work, following the winter rebuild, to do an inspection. These are the results. They were both about the same, a llittle bit of debris on each. Nothing big for chunks. I wonder if this looks like an acceptable amount?
Without going back through the thread IMHO what's on the plug right now could be very dependent on how well they were cleaned when they were torn down for rebuild. If I saw that on a component we'd installed I'd be having kittens because I know how clean everything is when it's rebuilt/reassembled. Very much a YMMV I think. I agree with you. No large lumps so possibly most/all the paste is from the previous failure. Clean the plugs, run the machine another 10 hours or so and take another look at them would be my advice.
That sounds like a good idea...........run another day & check it again.
That looks pretty normal on a rebuilt unit if you used new gears and stuff. I'd probably refill and run it a couple of hundred hours before dumping the oil again to recheck them. If you are nervous take an oil sample in ten or twenty hours. Did you save the oil and plan on putting it back in or putting new oil back in now?
Actually I had some extra drain plugs & did a "quick exchange" loosing a quart or two on each side with a catch pan underneath, just in case! Then just topped it up. Good idea to sample soon as well.
Did the oil sampling in the finals today & they are being sent to the Cat dealer. Ran the machine for a few hrs first to hopefully include any suspended particles present, if any.
There is a slim chance the sample could come back with high iron. Take note of the ppm and resample in 50 or 60 hrs. That will set a baseline.
Nearly all the final drives I have taken samples on came back with high iron. Take a sample now and then check in 100 hours. Look for silicon which will indicate dirt is getting in.
just fyi, my post above was actual experience, not just my "opinion". you won't need to check except at change intervals now, if it grenades like mine did you will definitely feel it. best of luck..
Here is the oil sample results taken from the finals on the D6C dozer. It only had about 35 hrs on it since the finals were rebuilt, when the sample was taken. I am not sure how clear the report is for reading? Everything looks ok according to the report. Maybe run it another 100 hrs & resample?
This may be a bit easier to read..........
No ISO Cleanliness Code on the analysis so there no idea of how many large (>5μm) particles are present. The microscopic analysis generally only measures the presence of particles smaller than 5μm. 39ppm of iron wouldn't necessarily worry me; 38ppm of Silicon indicatess it's got a load of dirt in it, especially at only 34 hours of operation. Either it wsasn't cleaned too well when it was torn down or you've got dirt getting in somewhere.
Just to elaborate a bit further, up to 50ppm of Silicon would be a value within the "normal" range for an oil sample taken at 1000 operating hours. Up to 65ppm "monitor compartment", and over 66ppm "Action Required" Your silicon value is 76% of the normal limit at only 3.4% of the hours. That's what would worry me most on your sample analysis.
Perhaps we should do an oil change in the finals straight up & then contiue the monitoring process moving forward?
TBH what I would suggest is get the machine well up to operating temperature & drain the oil. Fiill the final drive with a mixture of 10W oil & diesel and let it run with the track in the air on no load for 10 minutes. Drain & refill with new SAE50 oil and then see how it goes after 100 hours.
You should contact the dealer who processed the samples and ask their advice. They are the ones you are going to sit down with if something goes wrong. The dirt was probably in the new oil or the dispenser when you got it. Most of the big companies out here require new oil to run through a filter buggy to fill the compartments. I've taken samples on new oil and seen what you have there. Most of us little people wouldn't bat an eye at those readings.
I'm not sure I follow you here John. I don't think the dealer rebuilt the final drive..? I will say one thing though. The interpretation of the analysis results never mentioned anything like "contamination levels consistent with a rebuilt component" or similar, especially as it was obviously taken early when the oil only had 34smu on it. "No problems presently associated with this sample. Continue sampling at the normal interval" ought to be challenged. It sounds as though whoever did the interpretation completely missed the hours on the oil as a factor.
Here is the results of another oil sampling taken a few weeks back, being the LH final drive with an additional 150 hrs on the D6C. We sampled both sides, but for some reason the RH sample got lost & hence no results. I am a novice at reading the results, but see that the "Fe" which is iron is a lot higher...….any problem with that? Also, the machine is sitting at the yard now & we are ready to take another sample. Is it important for the machine to be active for a hr or so with the oil warm to get things mixed, or can viable sample be taken with the machine sitting, as we need to re-do the RH side now? The last sampling was taken when the machine was working with the oil warm.
You won't get meaningful results unless the machine has been worked for a while and the oil is at normal operating temperature IMHO. Also as you say the last samples were taken with the machine working and the oil warm, so if you did it sitting & cold you would not necessarily be comparing apples with apples. I'd be more worried about the amount of silicon (dirt) than I would about the iron. It very close to the reportable level right now. Is there a chance dirt is getting into the compartment through the seals or is there a possibility that the cases could have had contamination left in them when the FD was rebuilt..? The level at which iron becomes reportable is around 150ppm, but with more hours on the oil. Also the ISO from the previous sample in May at 23/21 meant that there were a fair number of larger particles (in the 5-15 micron size range) kicking about in the final drive at that time. It's a shame the ISO test wasn't run on the August sample. I'd suggest you get it done on the ones you plan to take now. Oil analysis result interpretation is all about trends.
I am not aware of any dirt getting in. Can dirt migrate in if there are not leaks, which is the case here.....all dry. I was not there when things went back together, but the person who did the rebuild was quite particular about cleanliness, so I trust all was clean. I could change the oil & start over I suppose & then monitor the trend again.
I’d see how the results of the sample you’re planning to take now come back before making the call to change the oil again. You should definitely ask them to do an ISO cleanliness test on it imho. What did the magnetic plugs look like..? Generally dirt can only get in if there is oil leaking out through a seal. As John C pointed out previously there is also the possibility that there is dirt in the new oil. If that was the case though, the silicon number ought to stay relatively constant.
Dirt could have infiltrated the sampling equipment and contaminated the samples previous. Been down that road.
We didn't pull the magnetic plugs in Aug. I am sorry, but don't know what the ISO test is comprised of? We can ask if necessary.
The ISO test was done on the first sample from May, but not the 2nd sample. I’d simply ask for them to do an ISO test on the samples you pull now, it’s obvious they can perform the test because they have done it before. You can see the ISO result (23/21) on the centre of the bottom line for the May sample.
Here's a bit of an explanation of how the ISO Cleanliness Code works. if there's anything you don't understand, shout out. http://www.apacheoilcompany.com/company-forms/ISO-Cleanliness-code.pdf
That's all well and good but the article is talking about hydraulic systems and not final drives in thirty plus year old dozers. Yes it is good to keep that stuff clean. In reality, most final drives in old equipment like this haven't had an oil change in many years and probably thousands of hours of use. I've sampled hundreds if not thousands of final drives in the last forty years and nearly all come out high iron. Does it indicate an imminent failure. No!. We just changed the oil and sent the machine back to work or down the road to the next owner. I've not had a come back. On the flip side I have had good oil samples and found broken teeth in the drain when the oil was changed. The samples were so unreliable that I've convinced most of my customers that it isn't worth the money or the risk of contamination to take final drive samples on oval track dozers. I check the oil level and if something strikes me as odd, such as water in the oil, level over full or way low, or a leak somewhere around the ham case or sprocket, I'll take a sample as a provable fact to show my customer. If the sample results bother you, then change the oil and take it again in a couple of hundred hours. Just don't lose sleep over one sample in the mid to high range for a final drive.
We did another final drive oil sample & will ask them to conduct the ISO test this time. Hope they don't loose a sample this time like they did last time!
Makes sence to me! Kelly
Just got the D6C final drive samples back via email this morning, these samples were taken with the oil warm after the machine had been working a few hrs. I see our sampler neglected to write the meter reading on the RH one (489 hrs) same as the left one. I notice the iron is up quite a bit, but perhaps it is ok as everything is showing green?
Start getting reports into the Yellow warning would be of concern, believe that to be over 500ppm. Engines can have up around 150ppm and still be normal(ring to sleeve wear) where gear train will show abrasive wear as well.
See the final drain plugs at 626 Hrs on the meter which would be about 330 hrs on the machine since the finals were rebuilt last fall. To me the accumulation looks reasonable. We are changing out the oil now & putting fresh in.
No chunks is a good thing.
I agree. The photos are not 100% clear but the accumulation on both plugs looks like what we call "fuzz", almost like a coarse paste. If it was mine I'd clean the plugs and put them back in, then pull them in another 300 or so hours of operation and take another look.
Well, its been about 430 hrs since rebuilding the final drives in Dec of 2017 so we did an oil change a couple of weeks ago. This is what is we found on both drain plugs. To me all looks good.
I think all looks good also.
Left plug nothing to worry about that I can see. Right plug has a couple of small flakes on it, but who's to say they weren't from the previous rebuild..? It's almost impossible to clean out every single flake when doing an overhaul like that. You've changed the oil anyway so press on and do the same plug inspection again at some future date would be my suggestion.
Will get pretty ugly initial wear in grindings no matter how new the parts are Not seeing anything there of worry where as Nige noted cannot clean the housings absolutely devoid of small particles