I have a leak coming from what I suspect the rear output shaft seal on an ax15 in my 98 cherokee. I'm looking to replace it but I just did the tranny fluid and I'm hoping I don't have to drain it before doing the seal. What are your thoughts or experiences from people who have done this before?

 

Is it the output shaft seal where the transmission goes onto the transfer case, or the output seal on the transfer case to the rear shaft?

 

Without having delved too far I am guessing it's between the transmission and transfer case and it seems to be transmission fluid not transfer case. The transfer case to both front and rear drive shafts is dry.

 

I dont think it needs drained to do the rear seal. just gotta get the transfer case off. might have to pull the whole trans/tcase to do it.

 

Transmission fluid as in "gear oil" (per the AX15 fluid requirements) or transmission fluid as in "Dex/Merc ATF" that is used in the transfer case?

I'm assuming you mean it's the new gear oil that you're seeing leaking out. If you're like me and use the MT90 or another high end transmission lubricant, I can understand why you wouldn't want to waste a $60 fluid change that you just did. (Bear in mind, you CAN drain the transmission fluid into a clean pan and put it back in after you're done. I know it's a PITA filling the thing, but it IS an option.)

Also, you might pull the boots off the shifter (from inside the Jeep) and see if it's dry around the shift tower. There are 4 bolts and a paper gasket between the actual transmission and the rectangular plate thing that hold the shifter to the top. If that gasket has failed you could leak transmission fluid out of the top of the transmission that appears to be coming from the transmission output shaft. A lot of guys will actually pour the new transmission lubricant into the AX15 at the top there since it's less arm work trying to pump it in with a fluid transfer pump.

 

It definitely would be easier to manage the seal with the transmission on a bench, but you can most definitely remove the transfer case without pulling the transmission. It might be a tight area but you could always drop the crossmember and tilt the transmission down a bit without pulling it off the engine.

If you're pulling the tranny off the engine, you might as well put a new clutch in (if it's anywhere near due) while you've got it apart.

 

I have seen this stuff stop a gusher of a front main seal leak (Ford 351), and a really bad power steering pump leak. I have also seen it really slow down an AW4 leak, and I have seen it do nothing at all to a different AW4 leak.

I think it depends on the type of seal and the reason for the leak.

It might be worth a shot.