95 grand cherokee pinion bearing

My front differential was leaking and whining so i replaced both the front and rear pinion seal. how ever i noticed that when i was replacing the rear seal the pinion bearing was loose and or going bad thus the culprit behind the seal gong bad and the sound. and my question is this how might i go about replacing said pinion bearing?  

Is your rear a Dana 44 or a Dana 35?

Both the front Dana 30 and the rear Dana 35, if that's what you have, have a crush sleeve to set the pinion bearing pre-load. I'm almost positive the ZJ Dana 44 has a crush sleeve also. The ZJ Dana 44 is a different animal than a regular Dana 44, which does not have a crush sleeve. When you remove the pinion nut and the yoke, you have disturbed the crush sleeve, and therefore the bearing pre-load.

It would seem like a simple job to replace the pinion seals, but it actually requires some special steps. At this point you'll have to guess at how much the pinion nut needs to be torqued. That's because you need to take a pre-load measurement before you remove the nut. That way the nut can be torqued to that measurement plus 5 in-lbs more. Also, the pinion nut is a one-time use nut. You must also replace the pinion nut with a new one or it will back off.

The nut must be torqued at least 160(D30) or 200(D35 & D44) ft-lb initially , and then gradually increased in 5 ft-lb increments until you reach the proper pinion bearing pre-load.

Since you didn't measure the pre-load before you removed the nut, you'll have to guess. You should at least have some resistance when you rotate the pinion yoke. You'll want to remove the wheels so that you can "feel" if there is some pre-load on the pinion.

As far as replacing the pinion bearing, that's not that hard. It does require you to remove the differential and remove the pinion.

The outer pinion bearing is a light press fit and you can just tap the pinion out with a brass hammer to remove it. The bearing will come out from the front of the housing. But the inner bearing is pressed on and you'll have to have someone remove it for you. Also, you'll have to tap the bearing races out of the housing. That's why you need to remove the pinion for the outer bearing. The race and bearing should be replaced together and while you have the pinion out, you should replace the inner bearing also. If the pinion has been moving around, both bearings are probably toast anyway.

Don't forget a new crush sleeve also when replacing the pinion bearings. You can not use an impact wrench to tighten the pinion nut, you must use a torque wrench!