EX60-1 Hitachi final drive - motor


My 60 is leaking hydraulic oil out behind and below the sprocket. It happened while my neighbour was off loading it from his trailer. It still travels fine, does not make any weird noise yet, it just is dumping hydraulic oil out the bottom.

I cant actually see where the oil is coming from...if it is the motor can I just unhook the hydraulic lines and unbolt from the backside? Or do I need to take the track, sprocket final drive etc off first.

Is there a seal between the final drive and the motor? Any advice is appreciated. Thanks, Grant
I just got done pulling the drives off a 331 Bobcat and a 312 CAT and most of them are made basically the same way, regardless of the machine size. That said, if the motor is leaking into the planetary housing then you might as well plan to have the whole thing rebuilt, or replaced. I say this because most leaks like that occur because the motor's output shaft is grooved allowing the seal to leak. If that is the case then it should be leaking hydraulic oil pretty steadily, causing it to build oil pressure in the planetary housing and blow past the seal. If that's happening, the oil level in the hydraulic tank should be going down. If your not losing hydraulic oil then the most probable cause is the planetary housing seal is just leaking. If that happens then you'll lose the oil that lubricates the planetary gears and the bearings, and that's not a good thing either. There are different types of seals used to seal the planetary housing but a leak is a leak regardless.

Either way you need to get the whole thing out to work on it. To repair whatever the problem is you'll need to start by pulling the track. Once the track is off unhook your lines and cap them. Being on the lowest point in the system they will usually leak oil to some degree as long as they aren't hooked up. Next look around the outside of the motor housing for a ring of bolts that holds the whole assembly to the track frame and take them out. If it's like the ones I just took out on the Bobcat and the CAT you might have to use a block of wood and actually drive the assembly out since they are usually a relatively tight fit in the housing.

Once out, I'd start the teardown by disassembling the planetary as getting into the motor is a bit more than most of us would want to deal with. Took the CAT I pulled straight to a repair shop since I knew the motor was bad. On the Bobcat the planetary was the problem and I started dissasembly there. Once I got into it and saw what all was wrong I made a few calls.

I knew I would have to go into the motor so I called the guys that did the 312 motor drive for me. He said often the smaller drives weren't really worth repairing once you got into them, expecially if you had motor problems and not just planetary problems. In my case, just to repair the planetary side of things was going to be nearly as much as I could buy a completely new assembly from from Bobcat. In this case it was around $3500, brand new, not reman (so no core involved). I even looked into an aftermarket drive. The guy there told me that if he could find me one to replace it it would be in the $3000 plus range. On the other hand he said most of the CAT, Hitachi, Komatsu, etc drives were in the $6000 range from the OEM but the aftermarket's on them were in the $3000 plus range, so $3500 for an OEM assembly wasn't a bad deal.

In the end it's worth tearing into to see what's wrong. However if the problem is much beyond just changing a seal then you might as well look into just replacing the whole thing as an assembly as it might be cheaper.
Thanks Wayne, great info - thanks.

So the order of disasembly is track off, hoses off, sprocket off ( or can I leave this in place) then unbolt the motor / final drive from the frame.

Or can the motor come off the final drive first?? Read somewhere about this????
I have a good hydraulics shop to deal with once I get it all out - this will be the worst part in my mind...

Thanks again, Grant
You can leave the sprocket on but taking it off will lighten the load a bit. Too, taking it off will give you a ring of open holes, one of which will work good to put a lifting ring into as you pull it.

In some cases you can pull the motor off the final drive, but typically the way they are made the motor's front housing is basically the rear of te final drive housing. In other words the two parts are integral with each other so there is no way to remove the motor alone/complete from the assembly.

I realize there are dozens of different types out there, and I haven't messed specifically with a Hitachi before, but in general what I have described so far is what you should be seeing, or very similar to it.

Below is a link to the place I called about the one for the 331 Bobcat. The guy I taked to was very nice, and as mentioned previously, honest enough to tell me that I'd be better off to get one from the OEM in my case. Never done business with them before, but to me honesty from a salesman goes a long way. Hope they can help you out if the need arises.
Excavator final drives
Thanks Wayne,

I will get it off the machine and see if I can come up with in locally. If not I will give those guys a call. I'm in Canada but not far from Washington State. I could get it shipped to a friend there. Good prices...

Thanks again, Grant

We pulled the motor off the final drive - it came off the inside and we didn't need to do the track etc.

The seals are blown and the hydraulic brake seals are also gone. Gave it to my hydraulic guy to fix. Hopefully we will have it back together in a few days ... then we will find out if the final drive is ok.

Thanks, Grant
Grant, we probably don't live far apart (in Canada) and I just went through the same shopping for my Kubota mini-excavator. The best price for a whole unit that I found was at Woodlands Fluid power in Texas. Very helpful parts man and everything worked out very well. They asked at the Border if it was for my business and because it was for my business it had to be "brokered" which we managed to to do ourselves with much sweating....LOL. Had I said it was for personal use, getting it across the border would have been easier. With brokering, however, the fee was 5%.
Thanks Eric,
Hopefully the motor seals will be the only problem. My pump guy is into it now...Otherwise I will try those guys.

Where abouts are you? I"m in Ladysmith on Van. Island.
Thanks for the update. That particular setup is a new one on me that I will have to remember in the future. I've only worked on a few Hitachi excavators but I have to admit they all did seem to have a well thought out design, for the most part.

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