Okay Boys, I recently bought a 1991 xj. The dude i bought it from said it needed a new transfer case for the 4wd to work. well long story short It's not the t case, it was the vaccum disconnect. well i pulled the axle out anywho to look at it. I opened the diff up to inspectt the gears. i filled the disco up with oil and it was running out of the axle on onto my knuckle. I did not fil the diff back up with fuild. do i need to replace my seal and bearing since it was leaking out? or do i need to fill my diff up and hope it doesnt all run outt my axle tube?
Any help will be greatly appreciated.

I did mod my vacuum disco btw

 

Your post is confusing, did you fill the differential with the axle out and the cover on or did you fill the axle with fluid with the cover off? The axle is needed to seal the fluid inside the differential.you might have just over filled it with the axle out.

 

Sorry I wrote it in a big hurry. I only filled the vacuum disco up. Which I think is the problem.

 

So you added oil to the vac disco, and it's leaking out the passenger side onto the knuckle? Sounds like a bad seal to me, but it isn't an issue I've dealth with personally.

When you say you modded it, what'd you do? There are a few options for bypassing it.

EDIT: For clarification, I'm assuming you removed the axle from the vehicle and left the axle shaft in the tube?

 

You are correct the disco doesn't get fluid. The seal is just to the inside of the vacuum disco preventing fluid from getting to it. If you swapped to a one piece axle then you need a new seal. I dont know exactly which seal but a quick search should yield you a part number.