Mustang 342 .......oil leak....help!

[dkmc]

I have an oil leak...underneath the left side drive motor, the chain adjusting plate has 2 large nuts on it.
It looks like oil is coming out around the threads of the studs.
Every time I move the machine and then it sits awhile, there is a puddle underneath it. And it seems like the level in the Hyd tank is getting lower.

Could it be one of the hyd drive motors has a leaking shaft seal and is filling the chain case up beyond normal levels?
Is that a common problem??

My plan is to drain the chain case, take off the chain case cover and operate the motors and watch for leaks around the motor shafts.
Sound like a good approach?

Thanks
dan k

 

[Iron@Dirt]

Put my 342 back together last year, small but a go getter. If hydraulic oil is dropping it could be just a connection on the motor or hose, they are pretty old by now. What engine do you have?

 

[dkmc]

Kubota 1402

The factory tech told me the motor shaft seals can develop leaks, and the oil leaks into the chain case.

 

[jwith68]

If you've identified the leak is coming from the chain adjuster cover, and that is above the normal "full" level of the chain case, it almost has to be coming from the drive motor shaft seal. There's really not any other way for them gain oil. How much oil have you had to add to your hydraulic reservoir? The chain cases are pretty high volume by comparison, takes a fair amount of oil to significantly raise the level in them.

 

[dkmc]

It seems to leak around the threads of the 2 large nuts on that adjuster "plate". I wiped it all off and thats where the wetness re-appears. That spot does not really seem to be -above- the full level of the chain case.

Manual says the Hyd tank is 15 gal and chain case is 5.5 gal.
The Hyd tank is low now.
Low enough that the pump makes 'starving' noises and the loader arms are jerky. I have used the machine a bit this past summer and it was not jerky. The level has dropped in the tank, but the only leak is as I described. I have not used it anymore till I address this leak issue. I have a shop manual but no parts manual. It looks like there may be a O ring around that adjuster plate as well??
All in all I can't see how else the Hyd tank can get low and the only leak is from the chain case....other than one motor shaft seal is leaking INTO the chain case.

I figure if I drain the case, take the chains off the motor sprockets,
and operate the motors, I should be able to see if the shaft seals leak?? The guy in service at the factory that I spoke with said that
this is a common problem and would explain the problem.

 

[durallymax]

There isnt a ton of room in there but I think you'd be able to see it.

I had to replace one of those adjusters on my FIL's 342 and IIRC there is an o ring behind it.

 

[dkmc]

Do you remember if it's a regular round O ring or is it a specially shaped one?

There isnt a ton of room in there but I think you'd be able to see it.

I had to replace one of those adjusters on my FIL's 342 and IIRC there is an o ring behind it.

 

[dkmc]

Tore into it today.....

The chain case had about 10 gallons of oil in it...supposed to hold 5.5 gallons. I drained it dry, blocked the machine up so the wheels were off the ground, and ran it at idle, operated the wheel motors with the chain case cover off.

Obvious the right side motor was putting oil out the shaft seal.
Took it out, and the shaft has some slop in it.....
Will disassemble tomorrow...

Any good places to get parts for these Char-Lynn motors?
Part number 109-1053-006

 

[jwith68]

If you do a search for hydrostatic transmission or hydraulic motor rebuilders, I'm sure you will find a source. I thought I had an external leak on the RH side motor in my 940, and found a shop near St. Louis that services all types of hydrostatic components. Luckily, I didn't have to use them because a closer inspection revealed a couple of leaking connector fittings instead of the motor itself leaking.

 

[dkmc]

Made some good progress yesterday.

Had to make some plates for my press, and managed to
press the drive sprocket off the tapered motor shaft.
Got the motor dis-assembled, and the outboard roller bearing
on the motor shaft is worn a lot. That is what caused the play in the shaft and is making the seal leak.
The rest of the motor seems to be in good shape with not much noticeable wear. I will go to the closest Mustang dealer first of the week and order a seal kit and some other parts.

 

[dkmc]

Update

Just getting back on this project, got the right side drive motor put back together today. Had to make a couple seal drivers and such.

Then I took out the 2 front axles to replace the axle seals.....
This thing had no gasket on the chain case cover, and has sat out in the rain.
All 4 roller axle bearings are shot.....rust pitted real bad.
I bet the back ones are bad too.
The water in the oil really wrecks things.......storing inside or tarping outside could probably save a lot of hassle in the long run......not to mention using the proper gaskets and sealing things up as good as possible.

More fun to come......

 

[ChrisMWood]

Made some good progress yesterday.

Had to make some plates for my press, and managed to
press the drive sprocket off the tapered motor shaft.
Got the motor dis-assembled, and the outboard roller bearing
on the motor shaft is worn a lot. That is what caused the play in the shaft and is making the seal leak.
The rest of the motor seems to be in good shape with not much noticeable wear. I will go to the closest Mustang dealer first of the week and order a seal kit and some other parts.

Hey dkmc! Just reading your posts. I need to remove the Nut off part of the drive motor and press it out. I picked up a non running 342, internal drive shaft on the motor sheared the spines. I don't have the rest of the motor, so I have a felling the Nut is going to be tricky to remove. Which size socket did you use to remove the Nut? I cant get a good measurement on it. I live out in Rural Australia with limited access to decent tool shops so will need to order online. My big sockets are all impact and wont fit in the cluster sprocket.