I found oil on the trailer deck under the final drive, from the seal area It was a few ounces at most, but we all know that does not just happen or heal itself either. What is a good plan? I could just top it off and see how it goes. Downside to that, if the bearing is damaged and I keep going, will I be making more work? I can easily take the track off. It is a new ITR track with the slip-fit master link pin. It is moving OK for now.
Is it overfull (and have hydraulic oil in it) from a possible drive motor issue?
I'll be checking that and draining the drive and looking at it for metal.
If the drive motor is leaking ( I am betting with you on this one ), is it worth attempting to fix myself without experience, or better to get a reman? I have one nearby at Brikers near Vancouver BC. I see it is a 125 Lb nugget with no handles, looks like joy to do
Don't remember much. Been 30 years since I had a 120 drive motor out. If it is like the larger machines, and I think it is, they are not too bad to do. The questions I would have is 1, make sure it is in fact overfull, and if it is why? If the motor seal is bad, is it because of age or because of a failure within the motor? 2, are the parts available? That is an old machine so a reman may be the way to go. Do you have the repair manual? Check your messages.
Fixing a hydraulic motor isn't as daunting as you may think. The biggest thing is hygiene. The kitchen table is good.Take note of the way it comes apart in particular lens plates. Check them for scratches, they can be lapped out if not to bad. Check the pistons and slippers in the rotating group for slop. If they are loose it will cause the casedrain pressure to increase, same with the lens plate hence the leaking seal
thanks fellas. I will get back to it Friday. Yes this is a straight 120, PC2592 in the parts catalog. Looks pretty daunting for this guy. I'm game to try with the help I have been given, thank you @mg2361
When all is said and done (motor wise) , still have to replace the duocone seal. .
Not necessarily Dave. I've had them stop leaking after replacing the motor seal and having normal pressure in the hub. My thoughts are is to check the condition of the motor and make any repairs and leave the planetary hub alone. If there's no leaks well and good but if the hub does leak then it's more than likely the bearing is cactus as well and they are hexy to buy.
That was what I was thinking too. Take the pressure away and good to go, fingers crossed.
I will drain the final and confirm hydraulic overfill for the leak, then start pulling the motor. I have started sourcing parts. One outfit in BC, Brikers, has a reman unit on the shelf for $3250 exchange with 380 shipping. If I go that route I may just go get it and visit my bro in North Vancouver. One place with most of the individual parts is Aspect plus in Kyiv, Ukraine. I would like to support anyone who supports those soldiers.
The bummer with getting parts from Kyiv is a month shipping delay. As much as I want to do it, I may just go with the reman that is close by if that is indeed the problem.
@Diesel Dave is on the right track, pun intended. I pulled the plug and it was just low, no hydraulic leak through or overfill. I drained it across this magnet tray and found nothing but some flour. My lazy self says add some oil every day I use it. That might mean 8~10 pints a year. I will explore parts availability and how much of a pain the job will be. At least the track comes off easily.
If anyone has the repair manual for this 120, I need the group 250 pages for repairing the gearbox to do the bearings and duocone seal. @mg2361 sent me the pages for the drive motor R&R and they reference this group 250 reference for gearbox repair.
@LACHAU posted a link for the workshop manual for an EX120-5 in post #5 in the thread below. HeavyEquipmentForums .
mg2361 hooked me up with all of it, including shop built tools to get it done. This looks like a pain in the ass. " Tighten nut (D) to 780 N·m (580 lb-ft) using DF1036A Propel Gearbox Nut Wrench (B) and DFT1109 Holding Bar (A). Fasten holding bar to ring gear (C). (See Section 99 for instructions to make tools.)" I don't even like reading 580 lb-ft. I strained an eyeball.
I sent the drawings for the tools to a friend with a CNC plasma table. A few hours later he sent me this picture.
Nice !!
I pour a half gallon in it each day now. It leaks out but the planetaries get wet. I want to get it back to the shop to take it down and change out the bearings, where I can get a little help with the big torque wrench and experience from an experienced guy I know.
I have the new bearings and seal in hand, so my friend John and I started into it today. The tools are great but we were unable to break that nut free. He had a 4:1 torque multiplier and we put at least 2000 ft lb on it before the 3/4" extension snapped off. There is a dowel in one of the holes to retain the nut, but it is tight up against it in the tightening direction. We need to loosen the nut to tap it back out of the way. I thought we would regroup before putting heat on that nut and possibly ruining it. What do you think is the solution, fellas?
I found a used nut in Buffalo, new nuts in India. NLA at John Deere. On a positive note, all of the planetaries look pristine in there, no sharp edges no end play nothing. I contemplate filling it with heavier grease to get by this job, but I still think it would make too much of an oil slick out on the job.
So nobody has any good ideas? Bad ideas?
Use John Deere corn head grease or OO grade grease from another brand. Be aware the JD corn head grease is polyurea based and won't mix with other greases or lubricants. It is designed/made for leaking gearboxes. I'd use another brand of OO grease that isn't polyurea based just so you know it's compatible with what was in the final drives. I forget the term but it is semi fluid, hydrodynamic maybe?? At rest it won't leak but thins out once things start moving. I used OO grease on a leaking track roller. I think it could be just what you need.
John did some research and he was prepared when we reconvened at the excavator today. He had the nut loose before I could see the process, I was moving equipment out of the way. He just couldn't wait! He borrowed a Swench model 1000 from another mobile mechanic. That thing is incredible. It has a big spring in it and a 3-lobed impact hammer piece that gets loaded up with spring force as you swing it 30 degrees. Then it releases BAM! Up to 2000 ft lb of impact force. It took 4 hits of that to knock the nut loose with no drama, no breaker bars, heat, crazy hammering or energy. Just pull the handle and it delivers impact blows on jobsites with no air. It works underwater. https://www.powerhawk.com/swench It was made by the Curtiss-Wright aircraft company. The design has been sold to powerhawk and Snap-On is the dealer. I picture it getting used on big radial engines to get the prop off. You can also find videos of it taking helicopter bearings apart. I wish it was fun and games after getting it apart. It was not. The ducone seals are really a PITA to get seated for assembly. It has this gigantic O-ring that provides all the sealing force to the two mating sintered iron faces. Each side is identical. The taper or cone that the O-ring sits in rusts up and requires wire brushing, and then the fun begins. You have to work it in carefully or it pops off the inside of the ring, or pops back out. The old O-ring was broken on one side. Timken tapered roller bearings. It was easy to drive in the races and we heated up the inner bearing to get it on the shaft. That is the seal pocket above the race. It is all back together now and greased up, ready to mobilize to the upcoming big digs.
You can find a swench as used military surplus sometimes. A lot of the surplus kits are incomplete.