Hey guys. Long time listener, first time caller. 1988 973 86G03557 I picked the machine up, ran it for 8 or 10 hours problem free. Then, When I moved the travel control lever it stalled a bit before moving and got worse until it wouldn't move at all, no strain on the engine when it won't move. Checked the transmission oil, it was low, like all the way. Added oil (which I realized after was thicker than whats called for) and no movement. After that we changed the transmission filter, drained the oil and refilled with SAE 10W Hydraulic oil. Started moving right away after that. While running it the left track would lock up every once in a while. (Suddenly, like a rock was stuck in the track.) After about an hour or two the stall started happening again. I changed the filter again, it moves but the track is locking up. The pedal which moved freely when I got it is now stiff, won't spring back on its own. We checked the oil on the final drives and they were overfilled with what is presumably oil from the transmission. Hoping for some insight. Much appreciated.
What pedal is sticking steer or brake?
Left steer. Same side the track is locking up on
It is all mechanical linkage. Pull pins at steering leavers on transmission, see if leavers move smoothly in transmission
Levers in transmission move smoothly with pins out. freed pedal up. Track still locking up when driving. Tried it with pin out/linkage detached. Same thing
Did you drain the final and check for chunks? Second I would get it out where you have some room and cap the brakes to do that there is a line that comes out of valve at top of hystat (transmission) and goes to a block on frame cap the line and block it is a jic fitting after you cap it start and pull it in forward do not hold in gear for more than 30 seconds! See if brakes will hold note I’ve see 973s not hold on first attempt to stall the hystat I would say if it does hold on second attempt to stall you probably got a problem with brake
Just pulled the plug on the final drive. Gushed a few gallons before I put the plug back in. No chunks. Just glitter. I’ll report back after the brake test. Thanks
Capped the line and block. When I put it in forward, the hystat wines in “pulses”, no strain on engine, no movement.
That's what it does I think you need to drain left final remove the center cover on left side final pull the axel and check for damage and play in planetary gears There is a treaded hole in axel you can put a eyebolt in to help you get it out. also there is a thrust button on the inside of center cap that seem to have a habit of coming lose bad thing is they are harder than the gears
Axel looks good, gears look good, no excessive play. Thrust button is where it should be. (flat disc pressed into the cover housing?)
Is all that cr@p on the pinion gear teeth metallic.? If it is then something is coming apart somewhere.
Yeah that’s metallic
That's good yes the flat disc pressed into the cover they usually crack the cover and come loose. before you refill it one more thing under the tractor on bottom of final there is a plug drain that and check for metal. some of the marks look like it was rusted and some of the other marks look like a lot of wear
Access under tractor not good at the moment. I wasn’t able to turn machine to get it out of the mud.There’s is a slurry of what looks like metal and oil deposited in the cylinder where the axel shaft is.
That's not good There has to be a lot of time on the final. was it still locked up you might be able to leave that axel out and get the machine out of the mud with one track or at least see if the planetary will turn
I’m pretty sure all of the transmission fluid came out of that final. Should I cap the final, refill trans and attempt to move it?
If you lost all the transmission (hystat) oil out the final you have a problem in the motor it could possibly have a bearing bad in motor that took the seal out I guess your going to have to put the cap on final and try to fill hystat if it is the motor you are going to have to get under it to get out.
Ok. It’ll be a couple days till I get to it. Thanks.
I was just thinking i don't think it would drain it completely I'd think it would stop at bottom drive line on hystat
So safe to move it with the level of oil in there?
No i think you would be safer filling it I was just saying you will need less oil
Ok got it
Ok, with the axel out the track moves free. I’m still in a tight spot but I’ll be able to get under it with a little digging.
There is a drain plug on bottom of final on inside might be a good idea to pull it and check for chunks might want to drain your transmission first to save the oil
Definitely some stuff on the plug if you can see the photo. I didn’t see chunks while it was draining.
Never mind . Lots of big bits were settled.
Sorta looks like bearing rollers bull gear only rides on one bearing and one thrust plate I'm thinking pinion is not in very good shape
Where would you go from here?
That wouldn't be too frightening depending on how long it's been since the mag plug was last removed and cleaned. The chunky bits is a whole different story........ To paraphrase the best furniture ads - some disassembly required.
First do you have anything to lift with every thing on the old girl is heavy I hate to say it but you need to get into final
I have a 5 ton mini and an old Dynahoe 190 at the moment
I think I would start by dropping track on that side lift front of machine with bucket put a good oak 4x8 between roller frame and track rails so when you put front end down it lifts sprocket out of the track remove sprocket guards from roller frame , remove planetary ,bull gear, you might have to rig a h bar to pull the bearing on sprocket remove sprocket then remove the hub by then you should be able to see the bull gear with out any real heavy lifting