2wd aw4 - how to replace seal so that it doesn't leak

[DeftwillP]

I'm seriously tired of replacing the output seal on the trans and having drip again later. I've purchased the replacement from oreilly as well as autozone I think. Dealer can't source one in time.

Seriously, does anyone know of a brand that will hold and not leak for say a year?


PS Jon, if you're reading this, I just degreased everything on the transmission and underbody and am going to check everything else for leaks once I get home for the weekend.

 

[Jeff in VA]

Might not be so much the seal as the slip yoke..is it pitted/rough, or worn @ the seal contact area? If it's not, try coating it with ATF before reinstalling it in a new seal (don't install it dry).
Jeff

 

[Rick Anderson]

I don't know if this will work, so I'd get a 2nd opinion before messing with an expensive slip yoke.

But if the slip yoke does not have a perfectly smooth and shiny surface that the seal rides on, that includes when the suspension bottoms out and drives the slip yoke into the trans, there has to be a smooth shiny surface an inch or two past where it rests.

If you don't have that, I'd take the slip yoke and emory cloth and clean the rust and pitting off in a crosshatch pattern on the slip yoke. I.E. run the emory cloth back and forth at a 45° or close to it, to the slip yoke axis.

 

[Atl XJ]

I helped a friend of mine with this recently. I had him get the OEM rear output seal and it look like 20 minutes total for the job and six months and 10K miles later it hasn't leaked a drop. I think the part was $30 but well worth it from all the threads I see about the aftermarket ones leaking.

Btw, I'm pretty sure it was a worn transmission mount that caused his to leak.

 

[5-90]

I usually use CR or Timken seals - haven't had any trouble at all...

Check the slip yoke (as mentioned,) and make sure there isn't a groove in it. Use your thumbnail to check it out.

While you've got it out, you may want to run some Scotch-Brite over the sealing surface of the slip yoke - I've found that it helps to "lap" the seal in a little faster and a little more effectively. Standard practise now for about 15 years.

Also, if you aren't putting a THIN bead of RTV black around the seal shell - start. I've sometimes found that a leak AROUND the seal will present as the seal itself leaking - and a little RTV is just cheap insurance against that.

Last, since you've cleaned everything off, make sure it's not the tailshaft housing itself that may be leaking - I've had to reseal a couple transfer case adapters (same thing...) and that takes about an hour and some RTV, since you've got everything torn to bits anyhow.

5-90

 

[8Mud]

Is there a bushing in the seal end of the extension housing? I seem to remember there is, but could be wrong. If the bushing is there and worn, it causes the shaft to wobble and wears the seal out fast.
I'm getting old and have worked on way to many AT's but seem to remember the bushing for the tail extension being non serviceable and the whole tail extension having to be ordered.

 

[DeftwillP]

Also, if you aren't putting a THIN bead of RTV black around the seal shell - start. I've sometimes found that a leak AROUND the seal will present as the seal itself leaking - and a little RTV is just cheap insurance against that.
5-90

The seal I have in there isn't that hold. I'll try the RTV trick this weekend.