Seal Leak, NP321

[coolwind57]

I've got this going on:  

 

I believe this is the reason my driveshaft and rear axle are all shiny and very-well lubricated....

 

I've never replaced a seal in a transfer case before.  Is it pretty cut and dry?  Lay on back in the gravel.  Drop driveshaft.  Pry out leaky seal with some needle nose or other clever technique.  Press in new one?  Top off?  That about right?

 

BTW:

 

Thank you, Gentlemen.

 

[COM86]

Yeah, I will also be interested in what someone will say. I have the same problem. But mine is a little worse. I believe that the seal on the front of the transmission is leaking too. And is killing the clutch...

 

 

[Warren Mohler]

This is an easy one, mark driveshaft to yoke position so shaft goes back the same seal can be pried out with a long screwdriver do not damage tailshaft seal can be driven in with small hammer or large socket don't hit rubber parts and lube seal with grease or vasoline in area of garter spring so it doesn't pop off seal put shaft back on yoke to where it came off, have at it.

[SVPete]

I have had the pleasure of doing this four times. Twice on the Comanche and twice on a Cherokee.

 

Safety first! Chock the truck. Parking on a slight downhill will help reduce transmission fluid spilling.

1. Disconnect the rear driveshaft and remove.

2. Using a long screwdriver, pry out the seal. You may need to use a screwdriver and hammer to try tapping the edge from the backside of the seal to get it started. Recommend you do not try to drive the screwdriver between the seal and extension housing case since the case is aluminum. A seal remover tool exists, I don't have one though.

3. Once out, clean up inside the extension housing case where the seal sits.

4. Install the new seal. It can be tricky to get started on. If you try tinking it on with a hammer around the edges, it will tend to keep popping out on you. You need something that can sit on the majority of the seal that fits around the splined shaft (like a enormous deepwell socket). I have a large adjustable wrench that I can open to fit around the shaft and cover 3/4 of the edge of the seal. Then give the wrench/socket/whatever a good rap which will get the seal initially installed. Obviously, don't hit the splined shaft. Then simply tap around the edges of the seal to completely install it. Of course, they make a real tool to do these kind of things too (don't have it either).

5. Reinstall driveshaft. Make sure to torque the bolts on the u-joint straps to spec. Recommend a drop of loctite on those.

6. Check fluid level on level ground. Fill to bottom of fill hole.

 

It's not that hard, but like anything you haven't done before, it can make you anxious.