My mechanic seems to believe my whine when moving my 98 xj is coming from the front differential. He has worked on plenty of jeeps before and I have full confidence in him. I really can't afford to spend the money it would take to have him do anything except repair the diff. Everything up to repairing the diff I can do confidently.The differential is black magic to me. I am curious as to whether or not I can just carry the differential to him to replace bearings or whatever or does he need to check for any sort of spacing before it is removed?
As much as I love to drive this thing, it has become a money pit, so I am trying to economize my jeep education.

 

If the bearings for the differential gears are bad, those are easily accessible once the diff is removed. In fact they want to fall off once it's out so you have to hold them in place when putting the gear assembly back in. There may be shims, but I would think that so long as you re-assembled in the same order as removal, you'd just replace the bearings and put the gear assembly back in.

If it's the pinion bearing that's bad then you need to take in the whole axle (attached to the vehicle, of course) unless you replace it yourself.

I would suspect the pinion before the gear bearings however.

 

The carrier and pinion bearings are a both a press fit they shouldn't fall out when you remove the carrier, the way to remove them is to use a bearing splitter and a press or cut them off with a grinder, you could also try cutting the cage and heating the inner race up and using an air hammer to chisel it off.

 

Yep. Bad news but still something to go on.
My thanks for your input.
My garage has grass floor and blue sky roof.

 

wrecker might practically throw an entire D30 front end at you, almost cheaper than the rebuild parts needed, ignoring shop labor ?

+ swap can be done free with hand tools in blue sky environment, and yr old D30 front end left over for spares

 

Might be worth it to get a whole axle from an XJ in a junk yard and swap it in yourself. They're cheaper than the parts and labor to replace bearings.

Just make sure the gear ratio is the same.

 

Front axle is $200 all day long. In a few hours you could have it in.
My "shop" has a gravel floor & blue sky roof. I've worked on stuff in the rain & August heat. It can be done. A Easy Up helps tremendously.
If you need it fixed IMMEDIATELY or don't need it to be a 4x4, ou can pull the axle shafts. The carrier will not spin or care if it's on the verge of failure or completely locked up.

Warning:
You will need to get a extra set of stub shafts & install in the unit bearings or they will literally fall apart.
Again, if you don't need 4x4 anymore, you could tear your shafts apart & reuse your stub shafts.
But 2wd ZJs are plentiful in the yards & will cure your issue for $50 or less.

 

Ahh..Hope springs anew! I will try to find an axle for it. Hopefully that differential has no problems.Yes, many thanks. I intend to keep the 4wd for winter, but that may just see me through. I have 3 vehicles in various stages of decrepitude and I am focusing my attention on this jeep before I start on one of these others.
Now if I can only find that front axle.
Then I can learn how to fix the bad diff.

 

Junkyard search to get you started:
www.car-part.com