I was asked to do a writeup on replacing the front differential isolator bushing so here goes.
I did not take pictures when I did this but will try to describe the process from memory since it has only been about a month since I replaced mine.
I did the job by myself in about 5-6 hours but with an extra set of hands it could have been completed in much less time.
The factory service manual says to remove the axles, drop the diff and change the bushings on the bench but when you work alone in the garage without a lift it is probably not the best option.
You will need the normal set of tools, sockets, extentions, jackstands, floorjack, etc. that is normally used to work on these jeeps.
The only special tools needed would be something to remove the old bushing and press in the new one. I used an air chisel to cut the old bushing and it came out easily.
I used a Harbor Freight ball joint service kit to press the new bushing in. (These kits can be rented at most auto parts stores.
Here is a picture i grabbed of the differential for reference. The only one bad on mine was the one at the end of the pinion. (Front left side of the picture)
Now on to the steps as I remember them.
Jack up the jeep and place jack stands so that when you let the jeep down the axles will droop to the limits. (normally the sway bars will limit the down travel and this should be sufficient.) I would try to get it up in the air as much as you can to make moving around under there easier.
Remove any skids or covers to allow you to access the bottom of the diff and driveshaft.
Remove the front driveshaft completely. (I just took both ends loose and left it laying out of place instead of fighting it out from under the jeep.)
Place a floor jack under the pumpkin and raise enough to take pressure off of the two bushings shown in the picture.
Remove the bolts holding these bushings to the frame.
Next remove the bolts holding the front bushing. (shown at the back of the illustration).
Lower the differential until the axle shafts rest on the bottom of the strut forks. (You may have to wriggle it around a little to get it to clear and lower.)
Remove the front bushing assembly from the pumpkin. (There are either 2 or 4 bolts attaching it to the pumpkin.)
You should now be able to rotate the pinion down and have access to the bushing on the end of the pinion.
If it is bad enough that you are having clunking, the center of the bushing should just fall our or you can knock it out easily. As I said earlier the bushing housing is a press fit so you will have to either cut it some way or have a special tool to press it out. (I have heard people say that they use a punch to mangle and fold it in enought to get it to release, but I used the air chisel to just cut the bushing and it released easily.
To put the new one in, I used some sandpaper to clean up a few knicks in the housing and polish the inside of the hole some.
I then used the ball joint service tool to press the new one in. (This tool looks like a big c-clamp and comes with various spacers and adapters to allow you to press the bushing in.)
You should now be ready to re-assemble in reverse order of the dis-assembly. (This is the place that another set of hands would really help because jacking the pumpking back into place while trying to stab the bolts is tricky when working alone.
From what I have found out in my research the pinion bushing is normally the only one with a problem. The front one would be easy to replace because it is a bolt on assembly. I think that replacing the one on the right would be more difficult because of not having room to get the press in place but it does not take the stress that the one on the pinion does so in most cases it should be ok.
I ordered my bushings from one of the internet vendors that I found with a google search. Sorry I can't locate the exact one but at the time I just ordered 2 since the pinion and right side uses the same one and I got them both shipped for just under $40. I only used one so I now have a spare in case the situation comes up again.
The part number is 52089516AB.
I hope this helps any of you that want to try this yourself. I know when I found out that it was going to cost $600-800 to have $40 worth of bushings replaced that I decided to tackle it myself.
I hope this helps if any of you guys decide to try it yourself.