How much, if any side to side movement should there be where the rear driveshaft goes into the transfer case tailshaft? I'm on my third or fourth (can't even remember anymore) seal and I'm getting tired of replacing them. The seal surface on the driveshaft is nice and smooth so I don't think that's taking out the seals. Any ideas?

 

The shaft usually has a little bit of play. I would give the transfer case breather a check and make sure it isn't clogged and causing pressure to build up.

Also, make sure the leakage is coming from the seal, and not leaking through the slip yoke. There is a metal cap crimped into the end of the slip yoke, right where the u-joint is. I have seen several leak there, and the repair is to replace the slip yoke.

 

I've checked the breather, it's o.k. The leak is definetly coming from the seal. Never heard of a leak through the slip yoke. Something to watch out for in the future though!

 

It sounds like you've checked all the obvious stuff. Unless you have a ton of miles on the truck, and the seals are just wearing out normally, you may want to go ahead and replace the slip yoke along with the seal. It may have just been machined to the lower end of the tolerance range during manufacturing. The only other possibility is that the extension housing where the seal is retained wasn't machined perfectly round.

 

hi
there is a bushing in the extension hoousing that prob needs replacing .
the bushing holds drive shaft yoke in alignment !

 

I have had two of those replaced under warrenty, for the most part they are just crappy seals.

 

I've used seals from a few different places, although they probably all come off the same assembly line. I'll have to take a look at that tailshaft bushing. As for the slip yoke, any ideas on the specs. for it? I'd like to check it when I get around to replacing the seal again.

 

My front drive shaft seal just started to leak. Is this as common as the rear? I have less than 30k on the truck.

 

That slip yoke should not have much side to side play in it. I don't have a spec, but it is meant to go in and out and with too much play side to side it would bind.

 

I have no idea as to the spec, and I have never found a source for it. As for the bushing, I don't remember ever seeing one cause a problem, but it is certainly a possibility.

 

I don't have much play, maybe a sixteenth to an eighth inch if I grab the u-joint and shake it. I may try to find a new bushing because I'm getting pretty tired of replacing seals.

 

I just recently experienced the same things you describe (rear tail shaft leak and small amount of play). I replaced the back half of the t case came with new seal it was around $90 bushing is inside as well . Purchased this from dealer Just needed a tube of silicone. No more leak play is gone. try it