Transfer case seal?

[89Suburban]

Has anybody here ever changed the seal on the rear driveshaft output on the transfer case? Mine is slinging some fluid up onto the floor.

 

[davbell22602]

Nope not me

 

[89Suburban]

I am bumping this up because I need to get this seal fixed, nobody in here did this before? I have been looking around and I see some people say that the yoke for the driveshaft should be replaced if you replace this seal? And I saw a parts kit that came with a seal and a bushing? Anybody? This is the rear driveshaft seal on the NP241C trans case.

 

[oneluckypops]

The seal kit is what you want.

Seals dont just start leaking for no reason, The outputshaft bushing is worn and causes the seal to leak. If you replace just the seal it will leak again.

 

[89Suburban]

Is it hard to do? Here is some of the kits I found on RockAuto.

http://www.rockauto.com/catalog/moreinfo.php?pk=1118426

http://www.rockauto.com/catalog/moreinfo.php?pk=1836208

 

[oneluckypops]

No its NOT hard to do but i would also reccomend replacing the output shaft bearing. Total rebuild time is about 6 hours including R&R

Heres a parts explosion on the 241 and 243

Bearing 12384947
Case Busshing 15665313
Output Seal 14095611

 

[HotRodPC]

The seal and bushing alone should buy you quite a bit of time if you didn't want to reseal the whole Tcase and new bearings just yet.

 

[89Suburban]

I think this rear output housing comes off the main case, so I'd just have to unbolt that and take it off and the bearing and bushing and the seal will be all in that one part? Is the bearing pressed on the shaft or housing or should it slide off? What about the driveshaft yoke, maybe the face of that is worn into grooves where the seal rides?

 

[oneluckypops]

been awhile but I think you will have to seperate the case, to get the bearing off of the Outputshaft.

 

[HotRodPC]

I think this rear output housing comes off the main case, so I'd just have to unbolt that and take it off and the bearing and bushing and the seal will be all in that one part? Is the bearing pressed on the shaft or housing or should it slide off? What about the driveshaft yoke, maybe the face of that is worn into grooves where the seal rides?

I do believe you have to open up the case to get to the bearing. The tailshaft is long and the seal and bushing should be in the end of it, and hold the yoke steady. That's why i suggest if you wanted to wait, the bushing and seal should get you by for awhille. Not likely to last 20 years, but you might get a few years out of it without replaceing the bearing. If the yoke had scored or grooved from the damage, then yes it should either be replaced. IF you have a 2pc driveshaft, and its got like 1/8 to 1/4 in play in the carrier bearing adjustment. Slide the carrier bearing either forward or backward so its in a differant position now and your yoke might just work fine. I've seen it work well before on a 3/4 ton that .... F all that . I just realized with the lenght of Tcase, you're gonna have singles dshafts.

 

[Swims350]

dang I thought you could pop the seal with a screwdriver or seal tool and drive a new one on it. But yea seals go bad, sitting in bad conditions dry rot and such. Other then that yea they can be driveshaft yoke or bushing or something gone bad.

 

[HotRodPC]

He can grab a hold of the dshaft and shake the **** out of it right behind the yoke. If it doesn't seem to wobble, rock or move much in the tailshaft, its possble the seal just got hardened and shrunk up. That woudl be best case scenario, but usually its at least bushing wear that cuase the seal to get beat on and egg shapped or made bigger round then it leaks. If its slinging the fluid, then its making its way to the dshaft and without doubt its the rear seal. If it was just dripping fluid, you could assume a seal somewhere else might be leaking. A guy I know, just had the similar problem in a 99 Tahoe. They charged him $350 to pull the Tcase and put all new seals, gaskets, o -rings and a new tailshaft bushing. So they say they did all that. I have to wonder myself, but I don't trust mechanics. Many are crooks.

 

[oneluckypops]

He can grab a hold of the dshaft and shake the **** out of it right behind the yoke. If it doesn't seem to wobble, rock or move much in the tailshaft, its possble the seal just got hardened and shrunk up. That woudl be best case scenario, but usually its at least bushing wear that cuase the seal to get beat on and egg shapped or made bigger round then it leaks. If its slinging the fluid, then its making its way to the dshaft and without doubt its the rear seal. If it was just dripping fluid, you could assume a seal somewhere else might be leaking. A guy I know, just had the similar problem in a 99 Tahoe. They charged him $350 to pull the Tcase and put all new seals, gaskets, o -rings and a new tailshaft bushing. So they say they did all that. I have to wonder myself, but I don't trust mechanics. Many are crooks.

Except Me hell thats one of the biggest reasons I quit working on autos fulltime

 

[HotRodPC]

I think that's why I always did so well on my own working on cars back in the day. I had fair prices, never ripped anyone off. I'd like to say I backed my jobs up, but I never had come backs, except for one on a Th350, when an idiot was at the races rolling in reverse, put in in D and stab it to do a smoke show. He broke the input shaft on the trans that was a month old. He knew I was there and seen it happen. He walks up and says, I bet that isn't covered in the warranty is it? I said HELLLLLLL NO !!! But, even then, I told him to bring it over, he pull the trans, I'd help, and I'll fix the trans and he can put it back in. So we did that one Sunday afternoon, but I damn sure didn't have to.

 

[89Suburban]

I did check the yoke for wobble and there isn't any at all. But the thing is the driveshaft yoke slides in and out as the suspension moves up and down, so I think just the seal is wore out. Which is opposite of the front driveshaft the the slip joint is built into the shaft itself and has a grease fitting. This truck does not have a center bearing either. And after I put those booster shocks on the back the yoke seems to be riding on a new spot, but I will try just the seal for now and see how it does, it's only a few bucks. I appreciate all your guys thoughts and input on this. I never did this particular repair before.