Leaking Final Drive

[Diesel Dave]

Here’s a pic below from the Deere online parts look up.
A Deere 200DLC is equivalent to your Hitachi Zaxis 200LC-3 .
Link to the parts page
https://partscatalog.deere.com/jdrc/sidebyside/equipment/83647/referrer/navigation/pgId/374915

 

[Vit]

I bought Bobcat 331E year 2000 with broken final drive (I didn't know about it at the time) and there was many other problems to solve around the machine so I was driving it for 2,5 years and didn't notice a thing. In May 2022 one of the two bigger bearings finally gave up

Obviously there wasn't oil for years (pervious owner had to give up oil refill too, didn't told me about that). New drive (in Europe) was approx. 5000USD, alternative was about 3000USD so I tried to rebuild that thing, total costs 916 USD + my time (I have minimum tools and no garage/workshop)

The rebuild went very well (if you ignore sweat, blood, multiple small injuries and a lot of tears), the drive is holding all the new oil in it no problem for next 4 months and counting.
At first I thought that problem is in hydraulic part of the final drive so I openned that first... it's a bit hard to put everything back together and keep it clean...
My profession is an accountant by the way, I never visited any "machinery" school or had relatives as mechanics, I just love to dismantle broken things and put them back together fixed (sometimes).
I want to say, that rebuild is possible, depends if it's worth it.

 

[Nige]

The special tool for the bearing nut is made of a section of tube, with "teeth" welded around one end to fit whatever slots are in the nut, the other end has a plate welded across with a spare socket welded on. I'll see if I can find one and take picture. Obsolete gas cylinders get kept in the junk pile for making these specials

Holding the final drive from turning is the only other thing to consider.

Could the nut be loosened before the track is split and/or the travel motor removed.?

 

[John Shipp]

Could the nut be loosened before the track is split and/or the travel motor removed.?

That would be my way of thinking.

 

[Diesel Dave]

Here’s a link to the parts page for the Zaxis 200LC-3 from the Deere site also.

https://partscatalog.deere.com/jdrc/sidebyside/equipment/65247/referrer/navigation/pgId/18375 .

Brandt the deere dealer has really good used parts dept that can find damn near anything , tho not necessarily the cheapest.
They generally offer components as new, in-house rebuilds and good used takeoffs.

 

[sdavies2000]

Thanks for the link to the parts diagram. That definitely helps me wrap my head around it. The thrust washers that have been mentioned here, are those the spacers (#24 in diagram)? If I pull this apart, there shouldn't be any need for me to open up the hydraulic side with the swash plate and pistons correct? I could leave that can of worms unopened.

I can't believe that drive worked for over two years dry like that!

I also have a love of tearing things down and rebuilding and consider myself to be pretty competent mechanically, that part doesn't concern me. What concerns me is not knowing what to look for in terms of parts being worn or out of spec. There's the obvious stuff but there has to be a lot of things that could be bad but could go unnoticed by someone that has never had one of these gremlins apart.

I'm going to start tomorrow by removing the covers on both drives and having a look to see what kind of crap is sitting inside there, I'll post pictures of my findings.

I appreciate all the feedback so far

 

[Nige]

I'm going to start tomorrow by removing the covers on both drives and having a look to see what kind of crap is sitting inside there, I'll post pictures of my findings.

The problem as I see it is that you only have a "leaker" on one side.
I would suggest to only go into that one right now. The other one I'd drain the oil, throw a couple of gallons of diesel in it, raise the track off the ground and run it in both directions for maybe 10 minutes or so total, drain, and if necessary repeat if what comes out the first time is still badly contaminated. Put the drained diesel in a bucket and swirl a magnet around in it and see what it collects. Refill with oil to the correct level for now, you can go back to it later.

 

[John C.]

I’d say to do your home work before doing anything else. Find your parts sources and possible pricing. Make your decisions based on what is affordable and possible.

 

[skadill]

The completely 'wrong' but cheapest bandaid way is to flush it out as said above, and pump half a dozen tubes of grease back in. I've done it and it lasted the rest of my ownership of a machine once.
Did the same with a swing transmission as well that was leaking out all around the swing bearing,no leak for next year or so till it got sold.( I also mixed that grease in a bucket first with half gear oil and warmed it enough to pour it in-slow process. Like tar, but doesnt weep past the seal.)

 

[92U 3406]

Problem with filling with grease, from my personal experience, is that it doesn't make its way into the bearings. Any one that I've pulled apart that had grease put into it burnt all the bearings and shafts.

 

[coalrulz]

The completely 'wrong' but cheapest bandaid way is to flush it out as said above, and pump half a dozen tubes of grease back in. I've done it and it lasted the rest of my ownership of a machine once.
Did the same with a swing transmission as well that was leaking out all around the swing bearing,no leak for next year or so till it got sold.( I also mixed that grease in a bucket first with half gear oil and warmed it enough to pour it in-slow process. Like tar, but doesnt weep past the seal.)

Witnessed underground coal guys use a similar method when the seals were leaking on a continuous miner cutting drum. I had not seen this before so I gave it a small chance of success, the gents putting the grease in said they had a "special" cocktail of grease and oil. To my surprise the cutting drum made it to the next rebuild.
Sometimes temporary fixes work, sometimes they do not and price to repair goes up.

 

[sdavies2000]

well I talked to Brandt, all parts are available (thrust plates, needle bearings, main bearings and seals) and looks like it would cost about 1500 in parts. If i do the work, that's doable but buying a remanufactured drive for 12k (CAN) isn't an option at this point so im going to start by doing what Nige suggested. I talked to the local heavy equipment service place as well and they said about 2k to tear down and replace seal, if needle bearings were also bad then they suggest a new drive which i dont understand because they are cheap. the needles bearings also have to come out to get to the seal anyway so im not sure why they scrap it at that point. I'll post findings tomorrow.

 

[92U 3406]

Technically the planetaries (where the needle bearings are) don't even need to be disassembled to replace the seal. Just remove each carrier assembly and set aside.

The fact your final drive may have been run low on oil I'd just order all the pins, bearings, thrust washers and split pins. I don't see the logic in junking the final drive if its only bearings.

Hopefully the shop is experienced with these final drives. If the nut starts to gall up when being threaded off they will destroy the spindle if they start heaving on it. In that case its best to split the nut off and touch up the threads on the spindle so a new nut threads on easy.

 

[sdavies2000]

Yes sorry, i just meant the assemblies that the needle bearings are part of have to come out. I'm feeling more and more like ill tackle this on my own and the actual track splitting will be harder work than the rebuild.

how does one remove the nut without damaging the spindle? i know they have a lot more experience than i do!

by pins, are you referring to the part that the needle bearings rides on and the split pins go through? the piece at the centre of the planetary gear. essentially the shaft right?

 

[92U 3406]

You can drill a close line of small holes, say 1/8" or 3/16", through the nut from the spindle outwards to the edge. Repeat 180 degrees across on the other side of the nut, then smack the areas you drilled with a sharp chisel and it should crack it in half. Just take care not to drill into the material under the nut. You'll also fill the main bearings with metal so replacement is advised.

Yes, pins/shafts. I guess shaft would be a more appropriate term.

 

[sdavies2000]

Is that necessary? Is that something you do if you don’t have the special tool or people do this just to avoid causing damage to the spindle?

every video I watch completely skips over this step

 

[Nige]

Is that necessary? Is that commonly done? Is that something you do if you don’t have the special tool?

Yes if you have the slightest suspicion that the nut could potentially wreck a very expensive shaft if it seized while it was being removed.

 

[John Shipp]

You'll still need some kind of tool to torque it up afterwards. Have you got the torque spec for your final drive?

 

[sdavies2000]

How does one know if it’s going to seize? Seems like something you wouldn’t know until it’s too late.

unless it’s breaks free and then binds as it’s coming out.

I Haven’t found any torque specs yet and the shop wasn’t much help in that regard.

heading out shortly to open up the cover on the dry drive and flush the other.

 

[Nige]

How does one know if it’s going to seize? Seems like something you wouldn’t know until it’s too late.

The behaviour maybe.? Once it has been "cracked loose" for the first time it should simply screw off the spindle using a relatively low amount of force. If at any moment after the point where it breaks loose the force required to turn it starts to increase that would indicate something is causing it to hang up on the threads. Stopping at that point and splitting the nut off would most likely not result in significant thread damage to the spindle, it's carrying on trying to turn it that would do the damage.