leaking hydro tranny

[plowmaster 0]

is there a common place for the tranny on my charger 12 to leak? it seems to only leak when warm. im not sure if the PO chaged it with ATF or OTHER? its got a new filter, i dumped in some ATF and it didnt seem to change the way it ran. i used dextron III

just curious where to look at after i give it a good warshin.

thanks.

[Sparky-(Admin) 19,680]

Around both axle seals I think. Also the hose connections for the hydraulic lift will sometimes leak.

Mike..........

[plowmaster 0]

no hydraulic lift here, just a driver side armstrong unit.

[kpinnc 10,990]

I'm gonna agree with Mike- It's more than likely axle seals.

Trouble is, most of the time it seeps underneath the tranny before dripping off. If that is what your's is doing, it will definately look like something completely different from what it is.

Kevin

[plowmaster 0]

ok ill clean her up and check there, seals should be an easy fix. ill take pics.

while im at it, should i give it a good flush with a bit of diesel before i drain it? im not sure if i have atf, hytran, or motor oil in it now. id like to run hytran (universal hydraulic transmission oil)

[HorseFixer 2,012]

while im at it, should i give it a good flush with a bit of diesel before i drain it? im not sure if i have atf, hytran, or motor oil in it now. id like to run hytran (universal hydraulic transmission oil)

Ive heard of guys who have done that Diesel flush but If I were you after adding The ATF I would run it awhile dump it again and refill with fresh ATF!

Duke

[Kelly 1,028]

I'm not so sure I would flush a hydro with diesel, I've done stick shifts, but not a hydro. The last hydro I did used 10w30 motor oil, it was a sunstrand trans in a 74 C-120

[kpinnc 10,990]

but If I were you after adding The ATF I would run it awhile dump it again and refill with fresh ATF!

Duke and Kelly are probably both correct. No need to flush that tranny, ESPECIALLY if it's filled with ATF. The fluid has very high "cleaning" properties, so you shouldn't need it.

When I replaced the differential in the Bronco, I was shocked at how clean the inside of the transaxle was. I've seen the insides of several transmissions, and this one looked brand new. To my knowledge, it had been a LONG time, if ever, since the fluid had been changed. It still had an old faded WH filter on it, and had been parked in a shed for about 10 years.

Not too bad for a 37 year old tranny...

On another note: When you check the axle seals, check the axle bearings for play. If the bearings are worn, new seals won't do a thing for you...

Kevin

[TT-(Moderator) 1,129]

Another place I've found to be a leak source on a Sundstrand is the seal on the direction control shaft on the "front" of the pump. (faces toward the front of the tractor) B)

[plowmaster 0]

thanks, the main reason for the flush is due to the fact i have no idea what is in there.

and am i correct in assuming the oil seals and axle bearings are common napa parts?

also, on the directional shaft, i do notice it leaks a bit more after alot of "back and forth mowing".

thanks for the help folks!

much appreciated!

[plowmaster 0]

well it sure isnt leaking at the axle seals, the axle tube is clean.

it looks wet from the top of the unit to the bottom, and much grime packed in around the front.

[TT-(Moderator) 1,129]

It sure sounds like the DC shaft seal is leaking. If you think about how many times they move back and forth in their life, (and how much dirt gets packed in that area that can wear the seal) it's easy to understand why they leak. That seal is NLA from Toro, but you should be able to find one from CR. (I forget the size though. )

There are some O-rings between the pump and motor end caps that can leak too, but you'll usually see the fluid running down over the left side of the hydro unit.

[WheelHorse_of_course 99]

:whistle: Well, the most common place for a leak would be the filter....

If it has ATF it should be obvious because it will look reddish on the dip stick.