On the D6C 10K 6516 I just picked up, when checking the final drives this morning & the right side is way overfull (2 gallons), so suspect a leak from the bevel gear compartment, as that would seem logical? Is it likely a seal on the shaft going out to the final on that side that is the culprit? The bevel gear compartment was low by about the same amount that the final was overfull. I will keep a close eye on it now that I know to see if one is dropping, while the other one is filling. What kind of job am I getting into to repair this? Also, from the motor back I only see one dipstick (other than the hydraulics & finals)......are the oil compartments common for the torque converter, transmission & bevel gear compartment? Would this unit have wet clutch's & brakes? Thanks a lot, Metal Man
Torque,Trans,Bevelgear and Steering Clutches are common oil. Need to lift out steering clutch and reseal the final drive pinion. Some press tools needed. Later Bob
Every model and type of D6C has oil-immersed steering clutches and brakes. The seals on the final drive pinion shaft are metal-to-metal "face" seals, the faces of which are held together under pressure from the thick toric rubber rings behind the steel sections. The rubber in the toric rings goes hard with constant high operating temperatures and many hours of work, and the pressure is released from the seal faces, so oil then gets past the seal. It's a fairly major task to get at these final drive pinion seals. You have to remove the floorplates, brake pedal shafts and cross-beam, hydraulic lever controls, seat frame, fuel tank and fender support brace under the tank. Once all the deck is clear above the steering clutch compartments, you have to remove the steering clutch compartment covers, then unbolt the steering clutches from their respective drive and driven flanges. To do this, means the tractor has to be in a position where it can be moved backwards or forwards about a foot, so you can access all the steering clutch flange bolts. You move the tractor by placing a bottle jack under a grouser and jacking the track chain. Once all the steering clutch bolts are out, you sling a small diameter wire rope around the ends of the brake band, and use a small crane or come-along to lift each complete steering clutch, brake drum, and brake band out. The wire rope sling is installed in such a manner that it pulls the ends of the brake band together to clamp the steering clutch drum inside the brake band. Take extreme care to ensure the steering clutch assembly doesn't slip out of the brake drum, when lifting it! After the steering clutches are out, you need a special Caterpillar press setup - which involves a low-height, double-action hyd ram (P/N 1S4233) and pressing adaptors - that are used to press off the pinion flange. Once the pinion flange is removed, the pinion bearing housing can be unbolted and lifted out. Re-assembly of the pinion flange to the pinion shaft after seal replacement, requires checking the pinion-shaft-shoulder to flange-face dimension. This dimension is critical in pinion shaft and housing re-assembly, and the dimension is supplied under "specifications" in the service manual. It pays to do final drive pinion seals on BOTH sides when the tractor is disassembled - and it also pays to check bevel gear bearing condition, and replace the steering clutch hyd release control, piston seals, while you have the steering clutches out. The whole job is about 2 days solid work for a couple of guys, and you most certainly can't do it alone. One last point - check the pinion bearing condition and replace the bearings if they look well worn. These are flat roller bearings, they are designed to, and can cope with, a lot of clearance to allow metal particles to go through them - but if the races and rollers are badly pitted or scored, or have done more than say, 2000-3000 hrs, then replacement is good insurance against another tear-down.
The overfilled finals are very common on those old machines and doesn't hurt a thing, particularly since they don't do a whole lot of work anymore. Once the oils are all at the same level, nothing happens. Save your money for other problems you are likely to see come up on this machine.
My thoughts are the same as John C. to much oil is a lot better than "Dust" I would check the breathers to the casings and let it develope, there is other areas that can let oil transfer in the F/Drives, like the intermediate gear bearing case, cracks in main case and steel pipe etc, the tooling can be made to pull things to bits other than a single acting hollow cylinder, to press things together CAT supply an adaptor to screw onto the Pinion and cross shaft, the D6D 1 is the 1 to get as its the same thread size but longer and works better, it cost's about £80, the D6D pinion has a short stub on the end before the thread section, this is the reason for the longer adapter, there is no need for the cylinder to be double acting for flange work.
to oz.. one guy can most certainly do it alone and I watched the guy who did.. in my field.
Thanks for your thorugh step by step approach to a proper repair... I appreciate that. See below for John C's comments. One thing that I failed to mention on my origional thread is that we only plan to run the unit 100+- hrs. per year, so it won't be out there going steady. Is an over full final drive likely to cause any problems if I just leave it, based on how much it is being used? Appreciate the comments from everyone.
Agree with John, we used to run D8's overfull if that happened until it needed teardown. If you keep letting the oil out of the final you will have to add to the trans
We had a D8K with the same issue. Ran the tar out of it. No problems.
Metalman, if all you plan to use it is about a 100 klicks on the meter, I would just keep an eye on things as there is nothing realy to hurt, the repair is easy to do by yourself, I near always work alone and I never have any trouble doing those little D6 back ends on my tod, tomorrow I am going to fettle a D6C that is new to a Farm, good chance of finding a lack of oil in the Banger I am thinking?
Changing just the pinion is not a huge job by any means. I had a final quit pulling on mine, pulled the pinion out because it was the easiest to get at thinking it was sheared off, but wasn't. But.. it's teeth were beyond use, so it was replaced along with all the other parts inside the final. point being it is an old tractor, and just about everything that turns will probably need R&R'ing anyhow unless somebody has been keeping up on it.
I am with John and DPete. Let it run if there are no other mechanical signs of trouble. Change the filters regular, and don't worry about the oil. I ran a 46A D-8H for about 4 years with the finals overfull like that. It never had a problem. That machine also had a bad seal that let the trans overfill with engine oil. If you drained it out, it would suck in a gallon or more an hour out of the engine until it stabilized. If I recall, it had about 30 extra gallons in it. We would change out the trans oil about once a year, and add a gallon or more an hour until it filled back up again. You had to be careful, because you could smoke the engine by lunchtime if you didn't keep up on the engine oil. Once it was full up, The engine used about a gallon a day and the trans and finals used none. All we did was change filters, and a little more often due to the compartments all having black engine oil in them. It was still the same way when we sold it off after upgrading to newer iron. One advantage of the high oil levels was that unlike the other D-8's we had, this one would not loose prime and freewheel when the slope got too steep. I am pretty sure the trans would have stayed in gear upside down, but I was not going to try it out. I was on slopes as steep as 1:1 with it and it never missed a lick. The D-8K's we had would bail out of gear on a molehill unless they were 5 gallons overfull, and if you wanted to work a 2:1 or 1.5:1, you better add 10 or more gallons from the full mark. I still hear the dreaded pump whine that you would get right before you went freewheeling down a mountainside.
now that was an interesting story!
Ok, thanks for the info re overfilled finals. Looks like the general consensus is to run, change filters regularly & watch things. Seeing your comments about the black oil in the back end reminds me...a while back before getting the D6C, we looked at an old D7F in Michigan & I was trying to figure out how black oil ended up in the finals & the transmission when I checked the levels & was thinking someone dumped used motor oil in.......your comments cleared that up. Does the engine oil migrate from the engine into torque converter & so on to get back there, or does it get there another way?
The most common oil transfer of engine oil into trans is rear crank seal BUT never say Always or Never. If a trans pump is engine driven it can transfer at the pump shaft seal. Also hoses and lines can rub on each other enough to cut through over time, transfering oil while all the time not leaking externally. Leave no stone unturned. Later Bob