Recently purchased a 1998 john deere 190e with 3500hrs which had one drive motor leaking. Still tracked and moved fine but was leaking from the cone seal at behind the sprocket. I have done a lot of looking to try and find any information about the drive motor which I found that my machine is basically a hitachi ex 60-2 or 3 and from the looks has the same drive motor as mine which is also a hitachi drive. I pulled the final drive off and was going to install new seals but don't want the same thing to happen again and possibly blow the seals right away so wanted to make sure I have a problem corrected if there is one. I do have hydraulic fluid in the gear side of the final drive so the shaft seal was blown as well. My question is I have been reading that these drives have a built in parking brake with seals that leak and blow out the other seals on the drive but looking at the part brake down on http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt am am not seeing what appears to be brake o ring seals. I have all new hydraulic filters and am going to flush system and am going to check by blowing out the smaller return line from the final drive to make sure its not clogged and actually replace that line seeing as it had a few small little splits up near where it T's in at the swivel joint. The one to the other drive motor is new but doesn't look like the drive was touched so doesn't appear the motor had an issue just the hose had a leak. Is anyone familiar with these machines? Is brake on these done by pressurizing both forward and reverse hoses when not controlled to track forward or backwards on that side? I had my hoses sealed up to prevent dirt entering with a thick plastic bag and zip ties and started the machine after repairing the exhaust leak I had on the flared manifold pip pipe up to muffler it pressurized both and popped the bag which I quickly turned off the machine. I just wanted to make sure that was normal before fixing the drive and hooking backup just to blow the seals again. Any help would be greatly appreciated.
#37 and 38 are the brake piston rings, #42 the motor mounting seal I think. Usually only requires on hose to be pressurized to release the brake. Most machines have a certain amount of backpressure in the hydraulic system due to cooler and return filter restriction, each work port on the valve has a make up check which will see this backpressure any time the pumps are turning, they're there to backfill cylinders that move faster than oil will normally flow through the valve spool so they don't suck air around rod seals, etc. I would assume that's what happened in your case. Do make sure the smaller line that tees at the swivel is clear from each motor all the way back to the tank, this is the case drain. Most likely leaker will be the brake piston seals.
thanks for the info plan was to order every seal and o-ring I see. Yea I am going to have a new return line made before I put the drive back in after I verify the return line is clear all the way back. Do you happen to know if splitting the drive to replace the seals truly requires a 50ton press on a mid size excavator. Would a 20ton or maybe 40 ton be sufficient to split the two halves. Break down of the drives doesn't look like rocket science and appears to be mainly snap rings locking most of the internals together.
I have not worked on these models, but I can't see why you would need anywhere near that kind of push to service one of these drives. The big ring nut #12 that sets the bearing preload will likely take some horrendous torque to snug it up, but other than that I can't see anything that needs huge forces to come apart or put back together. Maybe somebody with direct experience will chime in here.
Does anyone know the serial number of o-ring #42?
Deere/Hitachi 4154877, SUB FOR TH110468
I just had a hitachi uho-45 about a 30000 pound machine and the bearing retaining nut was quite easy to remove and it Literally fell apart no press necessary. I think the press comes into play if you are replacing the bearing races. There was a knock pin in the nut that u drive beyond the nut into the ring gear before u loosen the nut on this machine
The knock pinlooks like item 13 on your drawing and there's just enuff depth in item 11 for it to go below item 12
Loader 53, also check the casedrain pressure. If it's to high it will cause the shaft seal to fail. A high casedrain pressure would indicate a worn rotating group in the motor.