Hello our D7 had a catastrophic failure inthe rear gear train when we put everything back together it started to leak out of a breather (pressure relief) between the torque converter and going up into the transmission wall. As far as I can tell all the lines are in the correct places. Any help much appreciated
Could use a little more info here. So the transmission was rebuilt ? Torque Rebuilt ? and now you have oil coming out a breather ? It's the bevel case breather or a bevel case with the torque convertor tied in breather ?
Sounds like the torque housing is flooding.
Heres a view looking down through the floor of the cab to the breather. The torque was rebuilt but not the tranny. The breather it is on a tee with one end going to the torque the other going to the bevel case.
crap heres the filter for the transmission pump there was a some kind of nozzle for something in it
That nozzel thing is a hose tail, the amount of carnage on your screen sort of makes me want to pop out the transmission including the bevel gear, so both sections from the back case and possibly the torque again, I cannot think of any hose in the casings? the transmission on these can be removed leaving the bevel gear section still in place by removing the plug in wiring inside via the back plate if you want to go this route, but the best thing I would think is to remove the complete trans unit, how that hose tail managed to get into the screen is a marvel, if the thing still drives and you are going to do the work on site I would drive it up on 6" timbers as its easier to pop the plates off and drop the torque if you "Need To" the hoist mount is in the cab roof above the torque, again thats a lot of bits hanging off the magnets for a fresh dont drive line repair?? tctractors
To me that nozzle looks like the end off someone's oil gun which they've lost while filling it up.
I was thinking that before I scrolled that far down the page to read CM's answer ....... Also and while deferring to Tony's experience, I direct this question to the OP ........ just exactly how much line cleaning did you do when you had your "catastrophic failure inthe rear gear train" .....? Was this screen pulled and cleaned..? Were all the lines flushed..? Was the rear end case cleaned out thoroughly..? Were all the steel lines in the rear frame rodded out..? I'm thinking that if the answer to any or all of these questions is no or you're not sure, what you may be looking at is the last of the debris from the original failure. And if you're finding it in the mag screen where else is it ....? Still doesn't help get to the bottom of why it's puking oil out (I tend to agree with MT that it sounds on the face of it like the TC housing is flooding) but I also thing we ought to approach this issue in a logical fashion before starting to twirl spanners..........
Well I am glad we all agree on the hose tail thing, but you dont rebuild torques without checking a few points, screens and filters are a must do item, I always pop the transmission pump to bits and check its innards as its only a few O rings plus after all your looking right at it when you start getting stuck in, the transmission is on rollers the hardest part is draining the oil, I always hit a pipe onto the test port and start the engine up and let the oil pump out into a drum, you could look in to the transmission from the back case with the outer shafts pulled from the F/Drives or a pilot you trust not to run over you while he runs through the gear speeds and look for leakage, but for oil to pass up the breather pipe its most probably from the torque case, but thats plenty of shrapnell hanging off the magnets, I like to have a look inside em' with that much glitter, the torques dont have much to get fired up on, the bearing and seal rings are the usual items, the hard bit is undoing those snitchy little 12 point bolts around the centre, get it to bits is my thought, plus you might find some spanners in the case? tctractors
I didnt know the screen existed until i started having the problem. There are no more shavings after checking it again so i think nige is right about it being from the original failure. It does drive first and reverse work. The problem only seems to occur when the machine moves.
Words fail me, they really do .............. :crying
With any failure in the drive train the traney needs removed to clean out the houseing.
And the lines and cooler too. Later Bob
Hi arrowsmith,I'm no fitter and only have about 25 years owning and paying for the things.I know you don't want to pull it down....but my gut feeling after seeing that screen is to gut it completely.That pipe thing that's somehow ended up in their??????? horrifies me a fair bit.I couldn't sleep thinking about who 'fixed' your tractor in the first place to leave a screen like that.I wonder what the hell else is in there?Lord Lucan,Shergar,Bin Ladens grandma????. If you don't pull it down,the trash alone could damage the entire tranny and torque(again). Either way,you've got a wallet emptier there.Good luck with it.
I once had a driver ask me what caused the break-down, my answer was " Over Greasing" without a seconds thought he replied that he never caused it as he never greased it "Not Ever". Arrowsmith, you cannot play around with this sort of kit without blowing loads of coins$$$$ you need to realy step up the service situation, or get someone to undertake this detail in a correct manner that is going to enhance the viability of owning and running this type of equipment, or it might be a thought to Hire in things of this type and lower the risk that might be outstanding with this equipment, a D6R in the U.K. is a good mount that like any work horse needs care and grooming to get the most out of the Oats you stuff into it?? it would seem you have trouble within this area, my thoughts are study up some on what you have already done and what you are going to do, to polish up this tractor into a working mount? wishing you the best of fortune tctractors
Thanks for your help all, I didnt follow the correct procedure to clean all of the old debris. It seems as though popping the transmission is the next task. I should have made the thread before I started this project.
Put it down to experience - remember the man who never made a mistake never made anything ........ There are loads of extremely knowledgable people on here who will be happy to help and guide you through diagnosing and solving your issue. The only stupid question is the one you DON'T ask....!! For a kick-off. What was the "catastrophic failure" in the rear end that you mention in your original post and what exactly did you do to repair it..? Try to be detailed in your reply - photos of the failure/damage would be really good. I think you are right about popping the tranny, but as Tony says it comes out on rollers so it's not a major ball-ache - all it will need (to pull it and clean inside the housing anyway) is a few seals to be replaced. Remember to take photos when you slide it back out of the hole so we can see what's in there. Maybe the fact that oil is spewing out of the breather could be a lack of correct scavenging. While you have the tranny pulled back one (or more) of our resident experts will have suggestions about what will need cleaning/testing because if your original failure was a "hard" one (and it looks like it was from that screen) then there will be bits of metal everywhere ........ invest in some white cotton gloves - no bull, really - because when you come to testing the housing for being clean before putting any part back in place it needs to pass the "white glove test" to make sure there are no lingering metal particles still in there.
Boys the back of the transmission pump is dinked. I got it off at the very end of the day so I will get more pics tomorrow but if you look closely you can see the destroyed teeth
Just one more very good reason for your problem and the need to do a total tear down and cleaning. If I can help with any info I'll be glad to see what I can do. Nige and others here have more hands on with the dozers, I'm more of a loader guy but I do have access to Cat SIS online. Not sure of your S/N but I may have some D7 books if they would be of any help. If the D7 trans. was designed by some of the same guys as 966,980,988 loaders they should not be too hard to work on. It helps if you have lots of space to spread parts out and keep from mixing from one area to another.
As I said before, get yerself a pair of white gloves - you're gonna need 'em to make sure everything is cleaner than a clean thing ................