Rear seal leak?

[scmsltn]

I replaced my seal too and I still get leaks... I might try is again with a light bead of rtv

 

[CaRaZy]

It is the yoke! Very common problem. A quick fix that no one will know or see is pull driveshaft out clean inside yoke with brake clean the thoroughly blow it out or dry good. Now get some black rtv fast gasket and squeeze a very generous amount inside the yoke. Grab a piece of thin cardboard trim to the inside diameter of the yoke and use a socket to an extension and push the cardboard piece you made all the way to the bottom of the yoke. You will hear air coming out and most of the time a little silicone will come out where your nagging leak has been. Just stand up the driveshaft and let dry before reinstalling.

 

[scmsltn]

^^^

So are you saying the bottom of the yokes themselves leak? Or the where the yolk ends is uneven so the rtv tries to seal the imperfection?

 

[kemo sabe]

I would guess something like that because when I drive it regularly I don't see a spot. It's only there if the truck sits for a few days. And the drips of Trans fluid are coming off the end of the driveshaft.

 

[rhino]

Listen to CarAzy... He's spot on with that fix! Trans tech makes a little seal that goes in there, but I have had them leak. Silicone and paper towel is what we use. You can pull the tail housing and there is a "yoke sleeve" that has an 0-ring in it, that's what supposed to keep it from leaking, but like CarAzy said, the silicone works best.

 

[CaRaZy]

Thanks for the validation, nice to talk to a fellow transmission specialist.

To answer above there is a little weld on the back of the yoke that leaks over time. This is an acceptable fix unless you want to buy a new yoke. . .

 

[scmsltn]

Good info....thanks. Would you happen to have a pic of the part that leaks?

 

[CaRaZy]

Next GM 4x4 that comes in the shop I will make sure I take a pic but its not something that is really easy to tell by pictures.


If you have a 2wd with the same problem there is a metal collar inside tailhousing that has a o-ring that goes bad and lets fluid work its way out the weep hole in yoke.

 

[scmsltn]

Rhino do you have a pn or link for the yoke sleeve?

 

[1996*GMC*SHORTBED]

Go to any good auto parts store & buy the rear tailstock seal AND the nylon bushing that is in there & replace them both. Remove the driveshaft & degrease down inside the center of the yoke as mentioned before, where the breather hole is. Silicone a steel beer or soda cap down on top of the whole. They fit perfect. You can also weld the hole closed if you have the ability. The breather hole in the yoke, is there to allow pressure releaf when the rear end & suspension travels up & down, when the driveshaft then moves in & out of the tranny. Before you reinstall the yoke, sand the seal area with an extemely fine sandpaper or ScotchBrite pad. Grease the inside & outside of the yoke before installing it as well.