Track Motor Trouble Hitachi EX60

Got the slowdown on the right track yesterday that i most often associated with foreign object in track, but nothing there. If I wait a minute, then the track drives for a couple feet and stops again. no other hydraulic functions are afected. fluid OK. No bearing noises. same symtpom if i lift that side of machine and drive it without weight. there is a little leak of light (presumably hydraulic) fluid from the outside planetary side of the track motor. not high pressure, or at least high pressure not making it out. I would have thought the planetaries had a separate gear oil bath but maybe they are lubed by hydraulic oil, or maybe the lighter oil will travel more easily through that assembly and leak under the cap if the motor is leaking.

where to find an actual serial number on this unit is unknown to me. Has Model (EX60URG) and mfg. number (10C-1977) on plate riveted to inside of cab low on near the front. The parts manual lists three motors depending on serial number range. Exercising this morning to observe for any physical displacement of drive gear under load or switching directions heard a noticeable pop and bigger but not catastrophic hydraulic leakage, again pointing to a seal but definitely showing up at outer, planetary end of assembly. and the track still moves a half dozen feet before it slows and stops. no mechanical noises like poorly meshed gears or decomposing bearings.

There are 3 hex plugs in the outer cover which is actually labeled the "carrier" in the parts manual which I always assumed were for gear oil, but maybe not. the motor ounts against an o-ring on the housing and there is a more significat seal shown for the outside bearing of the planetary assembly, again, at the opposite end from the motor.

any experience with this machine or some hitachi or deere that might have somewhat similar design much appreciated.

brian

First thing to do, check the oil level in the planetary hub. If its over full then the shaft seal on the drive motor is leaking and the cause of that can be a worn rotating group in the motor. That causes the case drain to over pressurize. If you have good mechanical skills it's a job you can fix

Tones said:

First thing to do, check the oil level in the planetary hub. If its over full then the shaft seal on the drive motor is leaking and the cause of that can be a worn rotating group in the motor. That causes the case drain to over pressurize. If you have good mechanical skills it's a job you can fix

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thanks for your reply. i must not notifications set right. glad i checked back. There are plugs in the hub. one in the center and a couple peripheral. So is there a general rule like set a plug to two o'clock or something insofar as level. Would the fluid in the hub normally be gear oil then and hydraulic is leaking in? Nevermind, answered own question. Should be gear oil. and the plug slightly in from circumference just over horizontal line. manual scan attached. bad boy, didn't grok this check. now has work to do.

then I have to try to identify motor and it would seem possibly planetary parts to preserve new motor?

Don't know that my mechanics skills are the best but not the worst. I Was able to put new bearings into the swing box planetary set up where the bottom seal was shot and leaked out the gear oil.

The parts manual has no breakdown of the motor itself to show the seal you mention. There is a seal for the planetary assembly which I would guess popped from over full or even slightly pressurized once the motor seal failed.

I'm checking both used, rebuild, new stock and trying to get correct part numbers. 3 different ones used on EX60. Not sure how interchangeable. Gotta get some measurements and identification info going. the full assemblies with planetary gearbox and including the motor are listed as 9069295 , 9096479, and 9138927. That was through parts manual 107-1-7 vs. the earliest parts manual i can find which is P10C-1-1 that coordinates with my manufacturing # 10C-1977. I'm pretty sure I am on the early side of the model. No years listed in any of the parts or operating manuals i have but I think I once traced this to around 1991.

If the planetary hub is over full the only place the oil can come from is the hydraulic motor. Although it not shown there should be a seal on the output shaft. It will be a viton lip seal and can be purchased from any reasonable bearing supplier, there's no need to find one from the machine dealer. When working on the hydraulic motor cleanliness is your best friend and take note of the way it comes apart. Inspect parts for wear like scratch marks on the swash plate, worn slippers and damaged cups etc. Believe it or not hydraulic motors aren't that complicated.
After you've done it ensure that the motor is full of oil before startup. Also drain, flush and refill the planetary hub.

Tones said:

Although it not shown there should be a seal on the output shaft. It will be a viton lip seal and can be purchased from any reasonable bearing supplier, there's no need to find one from the machine dealer. .

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that was true with swing box panetary seal as well. Since I have oil relieving out the planetary cover, it may just be overpowering the planetary seal with pressure. is it worth a try to put seal in motor and drail/ refill planetary and run it or should i break down the planetary.

you mentioned the possiblity that wear in the planetary could have lead to motor seal failure. if there aren't absolute meltdowns, filings or obvious noises of distress from within the planetary and the motor seal is not hard to replace thought it might be worth a go and see how long before it fails again?

This is the COMPLETE Parts Catalog Manual for the Hitachi EX60 Excavator Equipment Components. Designed for the repair shops and individuals when ordering parts for their Hitachi EX60 Excavator Equipment Components. This Manual describes and illustrates assemblies, subassemblies, and detail parts needed for service replacement. it Covers every part of your Hitachi EX60 Excavator Equipment Components inside and out. Tons of pictures and diagrams at your fingertips!

PARTS CATALOG MANUAL CONTAINS:
=========
PUMP
MOTOR; OIL
VALVE
CYLINDERS
PARTS INDEX

archibaldtuttle said:

that was true with swing box panetary seal as well. Since I have oil relieving out the planetary cover, it may just be overpowering the planetary seal with pressure. is it worth a try to put seal in motor and drail/ refill planetary and run it or should i break down the planetary.

you mentioned the possiblity that wear in the planetary could have lead to motor seal failure. if there aren't absolute meltdowns, filings or obvious noises of distress from within the planetary and the motor seal is not hard to replace thought it might be worth a go and see how long before it fails again?

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The gears and bearings may very well have survived . If it were mine I would just replace the seal on the motor and take a punt on the rest. What you don't want is oil leaking from behind the sprocket so drain the oil back to the correct level and fix it ASAP or PDQ .

There are two things on these that cause the planetary case to pressurise and force oil past the floating seals of the planetary casing. Motor seals or is ton seals on brake between motor and planetary casing