My D8H recently began popping out of gear and the steering clutches won't disengage. I assume this is due to a loss of pressure in the transmission pump. Pulled the magnetic screen on the suction side and found lots of debris including what looks like roller bearing material. About 1/8" to 3/16" diameter, 1/2" long rollers. Anyone able to provide any clues as to where these may have come from? Thanks!
Rollers are probably from a planetary gear bearing. Brace yourself - transmission out time.
Thanks for the reply. The previous owner of this dozer had a transmission go out and replaced it with a used unit shortly before I purchased it. I have owned the dozer for a year and put about 100 hours on it. I cleaned that magnetic screen about 50 hours ago and found what looked like bearing cage material. The metal in the photos is what as accumulated in just 50 hours of run time. Do you think it's possible this debris is from the previous transmission? (wishful thinking)
Not likely seeing as the screen is part of the transmission, so the one that is in there now would have gone in with the used transmission installed by the previous owner. Also bear in mind that you have other symptoms as described in the OP. I'm all for positive thinking but in this case I'm positive it's fcuked......
This is the screen that is forward of the pump on the right side of the engine, behind the large hydraulic filters. On the suction side of the pump, not part of the transmission.
My bad. I was thinking it was mounted directly on the front of the transnmission case. Either way I think you're being optimistic in thinking the debris was from the previous transmission failure before the machine came into your ownership.
Like Nige says I too like to think positive but..... Yes it is possible that some of those bits are from a previous failure BUT any place the oil has gone to in that transmission has now been contaminated either from this or a previous failure. To think that you can just replace some easy to access part on the outside is wishful thinking. I think you would be better off buying some lottery tickets, then if you win big you can buy a new machine. And make note of my saying anywhere the oil has touched inside that transmission is contaminated and that includes all hoses and oil cooler.
Not that this will change anything, but what's in the other two screens and the filters.
If the previous owner installed a used transmission, and didn't clean the suction screen and magnets, that is pretty revealing of his approach to repairs. The problem with purchasing and installing used transmissions is they generally come out of end-of-life tractors that have end-of-life components. The bottom line is you have a severe reduction in oil pressure, and along with major transmission debris, that means you have major transmission problems that can only be cured with transmission removal and examination. Be prepared for some major expenditure if you want to get the tractor fully serviceable again. As kshansen has said - don't forget the transmission oil is shared with multiple components and systems, and this means there's likely to be trash and metal throughout all those systems. The transmission filter is a bypass filter, so it dumps trash into the lube system when it becomes overloaded. The steering clutch hydraulic system contains spool valves with tiny orifices and those tiny orifices can block up with particles and cause you grief. So a thorough lube system clean is also on the cards.
Especially in the power train oil cooler.
This looks a lot like our D8H’s trans after a major failure. There’s not much good to report to you other than the machine may have had its final dance. That is unless you’re someone with the time and experience to repair. The men here on HEF have seen and done most of this work before and it’s not an easy repair because of the sharing of oil between systems. You’ll be looking at fully tearing down the machine from the engine back to clean her up and then you still have to find the parts. They’re out there but they are getting steel vs the cost of a later model machine. At this point you might be on the same island as we are in that we’re looking for a machine in need of an engine that we could transplant ours to and have a runner again. Sad days….
Did you get a chance to dig in any deeper. I'm curious if there's thrust washer material in the filters. Another thought. The screen under the seat may have been eliminated if your machine has a late production date. Don't remember for sure.
This is one of the main reasons I don't care to spend untold thousands of dollars on these old machines (that are extremely over priced). Its like a box of chocolates you don't know what your going to get, the transmission and system metal pollution is one thing, what other metal fatigued item is there that is hiding some place else that is going to let go next? You don't buy these old clunkers to run, you buy them to spend more $ and to work on. So if you don't like spending time and money to work on a dozer (wrenching work) you don't get one of these. There are all kinds of fun things that can break and get messed up on them. I've seen cases of 30K (dealer) spent to do major work (Not U/C) and then have the engine seize up. It can be a crap shoot some times.
In all the transmission repair is not hard to do or a bad job to tackle, I don't mind doing them or anything in the back end but the bits are starting to become harder to find at times, the powershift does make for easy driving, in the U.K. there is still a few D8H Tractors running with a strong love for the Direct Drive Series 235 and 270 bhp, this is a reflection on there inbuilt strength and very reasonable fuel consumption being 300 liters or less for a long shift, plus they seem to last 20 plus years on a G/Box before you need to think of looking inside, once you have the transmission out the other bits are simple enough to get at and work on, the oil coolers on a D8 need cleaning in the water side at least every 3 years so flushing out the oil side is not a big deal adding only a small time to the job, the Torque and divider are right handy to get at and easy enough to check through, the whole job is best done by yourself then you know exactly what is going on, its all straight forward enough with the spanner work, getting good parts new or used might involve a few calls.