Transfer case seal

[one4fun]

Got a very slow leak in the rear output shaft of my NP208. But, still a leak and needs to be fixed. Is the replacement as simple as popping the old seal of and putting the new one in, just like a rear seal for wheel bearings?

I was going to park it on a slope, nose down to keep from losing fluid if possible.

Thanks.

 

[bucket]

Yep, you just have to be careful tapping it in there if you don't have the correct driver.

 

[one4fun]

Careful not to bend or distort the seal?

 

[marks86]

you should replace the bushing that's inside the tailhousing also

 

[MadOgre]

That would require removing the tail shaft housing though

 

[bucket]

Careful not to bend or distort the seal?

Yup

 

[one4fun]

Got it replaced, easy as expected... but, it still has a ssssslllllloooooowwwww, leak. It's between the yoke shaft and the rubber ring. I'm thinking the shop must have done something to polish it down when i had a new driveshaft built a few weeks ago. Is it possible/likely that they did something that would have removed some material making the slip yoke and the rubber ring not seal? Fluids is at the right level, used Dexron III. is there anything i can use to coat the outside of the shaf to seal it up better?

 

[marks86]

you should replace the bushing that's inside the tailhousing also

you need to do this and it should stop leaking

 

[MrMarty51]

If You did`nt use some good sealer like no.1 Permatex around the outside of the seal and, the inside diameter of the seal housing, it will leak.
Also, did You pack the seal with grease, around the tension spring, so the spring would not pop out of its seat, when being driven into the housing. These three things are the biggest cause of a new seal failure.
It takes a LOT of emory cloth and sanding to take nough material off of a yokes sealing surface to cause it to leak. Probably not that. If the yokes sealing surface is smooth, without grooves around the circumference then, it should be OK.
If the yoke is not of the slip yoke design then, the washer and the under~neath of the bolthead will need sealer around them too, to keep fluid from leaking past the splines and from under~neath of the bolt head.
I am NOT saying that the yokes bushing is the problem but rather, I have replaced a LOT of seals over the old bushings and had no problems whatever.

 

[marks86]

there is a reason why the seal and bushing come together as a kit..http://www.napaonline.com/Catalog/C...haft-Seal-Bushing-Kit/_/R-NOS18998_0073941573

 

[one4fun]

Ok. I'll pick up a bearing/seal set and follow these steps. Thanks for the info.

I'll update This thread with my "success" story.

 

[one4fun]

Oh, so when I remove the tail shaft housing, are there any parts that will move or come out? Is there a gasket around the housing that will need to be replaced when reinstalling?

 

[marks86]

the housing is held in with RTV, you will need to disconnect your speedo cable and undo the four bolts to take off the housing.

the housing might take a little persuasion to get off, be careful its alum.

the housing holds the output bearing, bushing and seal

 

[flyboy1100]

I used Yamabond when i rebuilt my tcase. so far so good! slightly more expensive than RTV but works extremely well. Hondabond, suzukibond, fujibond, threebond all kinda the same. you want the semi-hardening one.

 

[MadOgre]

You should be able to pry the housing off. DONT HIT IT! I don't think you need to bother with sealant and grease for the seal but I guess it cant really hurt anything.

The trick is the bushing like Mark is saying.

The bushing stops the yoke from slopping around on the tail shaft. If its slopps around while going in and out and round and round it basically is prying open the seal sporadically allowing ATF to escape the seal.