955L tranny oil puking out of breather

[guisep3]

Ok guys I have a 85J 955L that I’ve owned for years now. My guys and I went thru the machine last winter and changed all the oils and filters with cat filters only in bevel gear, tranny, engine…etc

Well my guy over filled the transmission with too much oil for starters and we noticed it was puking oil out of the breather when we traveled back and forth. I tell them to PM equipment before we start our days in the job. Found the tranny overfull by quite a few gallons. We drained the excess oil out and still the same result of oil puking out. Then we proceeded to drain the oil completely out of tranny and replace with Cat 30W. My thought was maybe the guys installed 10W instead of 30W and it was emulsifing and building pressure.
Well the oil change again hasn’t helped. When operating the machine it feels perfectly normal shifting through the gears.

Anyone have any idea why the oil is coming out of the breather? Is it possible that the excess oil that was installed previously is still puking out despite a complete drain out and refill to the correct level?
Is this an indication of a blown internal seal? Really like to avoid removing the tranny from the machine. She’s in about the best shape possible for a machine of her age. I’ve also considered selling machine but hate to think of it being devalued for a small leak like this. We’ve put 100s of hours into fixing every other small leak on the machine and now this hiccup!
Any help is very much appreciated fellas!

 

[Dave Neubert]

acierating of the fluid can cause this

 

[guisep3]

acierating of the fluid can cause this

Could you explain what this means please? I did replace the oil with Cat 30w.

 

[Nige]

Oil getting bubbles in it - usually from a leak somewhere in the suction side of the power train oil system.

 

[guisep3]

Oil getting bubbles in it - usually from a leak somewhere in the suction side of the power train oil system.

Would I be losing oil in another system? The bevel gear and tranny are connected together correct? You think I’m leaking oil from the bevel gear? Making oil in the tranny?

 

[Nige]

Not necessarily. You can have aeration taking place without oil transferring from one system to another.
I would suggest that you should check the oil level in the bevel gear & steering clutch compartment to see if it is dropping.
At the same time you could investigate whether or not the transmission is overfilling.

 

[lunghd]

Oddly enough - this same problem with my IH125c brought me here and sounds like we've had the same issue: over-filling after a repair/maintenance. Will follow this one with interest.

 

[Dave Neubert]

Oddly enough - this same problem with my IH125c brought me here and sounds like we've had the same issue: over-filling after a repair/maintenance. Will follow this one with interest.

probably the hydraulic pump leaking into tranny

 

[lunghd]

probably the hydraulic pump leaking into tranny

Yeah, that's my fear and there aren't any hoses where it's leaking (at seam between pump & transmission. Was hoping it was due to both transmission & pump being slightly overfilled.

If it keeps losing fluid I'll start another thread, don't want to hijack this one.

 

[leadfarmer]

You could replace the breather with a pipe fitting and a hose to collect the fluid being pushed out and observe if it is bubbly.

The transmission drives the main hydro pump, the transmission pump, and the steering clutch pump. It's possible for seals in those pumps to go bad and alter the fluid levels in the machine.

In my case with my 85J 955L, I had a bad transmission pump move fluid from my transmission to my bevel gear case (the steering clutch pump and transmission pump are piggy backed and share a common drive shaft, the transmission pump pushed fluid into the steering clutch pump which dumps into the bevel gear case reservoir).

So short of any other information, I would get the fluid levels right in everything, then operate the machine awhile and observe where excess fluid in the transmission is coming from. I believe all the fluids should be checked with the machine idling and make sure it is on level ground.

If fluid levels in the bevel gear case and main hydraulics do not change then you have something going on inside the transmission causing the problem.

There is no separate clutch fluid level, that fluid is in the bevel gear case.

Review that you have replaced/cleaned the following: the steering clutch filter under the seat, screen for the same under a cover on top of the bevel gear case, the transmission filter, and the transmission screen. Each of those 4 items is under a separate cover.