I'm getting some noise from the front diff on the 97 Grand Cherokee (ZJ) that I've just done the motor swap and electrical repairs in. It's been suggested that it's a bad pinion bearing. I've never worked on one of these things before; been reading the manuals but don't yet have a clear picture of how it's built.

Where is the bearing - on the inside or outside? That is, do I just have to pull the CV cup and the bearing seal from behind to get at the bearing, or do the guts have to come out so I can pull the pinion out the front to get at the bearing? And if the shaft is scored, has anyone used a repair bearing (sleeve and bearing) kit?

Judging from the assortment of RTV colors I found when I pulled off the cover, it's been off a few times before. Does that suggest I'll be replacing the collapsible spacer as well?

Thanks much.

Jonathan

 

It would be more cost effective to swap the axle out with one from the local boneyard. To replace the pinion bearings you need to remove the axle shafts, remove the carrier, pull the pinion gear out, press the old bearing off, press the new one on, check the pinion depth and the list goes on. It can be quite time consuming and expensive.

 

Sure, but what assurance to I have that after doing such a swap I'm not going to have a replacement that's as bad as or worse than the original? How can I check the junkyard diff to confirm it's any good?