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-   -   Differential pinion mount/bushing replacement (http://www.jeepgarage.org/f181/differential-pinion-mount-bushing-replacement-31991.html)

99formulam6 12-03-2011 05:42 PM

Differential pinion mount/bushing replacement
 
Hopefully this will help other people if they should run into the same problem. I have seen other threads, here and on JF, but not all of them have the drawing/pics and all the parts and prices.




Well, I started getting a clunk when going from reverse to drive and after searching determined it was the bushings on the front diff that needed to be replaced. There are 2 actual bushings and the other one is an actual mount with a bushing inside and comes as one assembly.

Since I did not know which of the 3 were bad, I just bought all there. Total for all three was about $180 shipped from www.justforjeeps.com (the mount is over $100 alone).

I put the Jeep on the lift and looked at the bushings, and only the one on the front of the diff looked bad, the other one on the side of the diff looked fine, and I couldn't really see the one on top. I figured since the one looked pretty bad, and the other looked fine, I could go the short route and only change one on the front. To change the one on the front, you only have to unbolt it and put the new one on. To change the other 2, you need to remove the front drive shaft so you can rotate the differential to reach the one on top.


It took me about an hour from start to finish (and I was really taking my time bc my wife kept calling) and it was pretty easy to change just the one. Unfortunately for me, I needed to change the others since the clunk is still there.

So, as a note to everyone else: change them all, and save time in the end since there is no way to pinpoint if it is only one, or just 2. Might as well just change them all.

Here is a pic for reference. #1 is the easy one since you don't have to disconnect the driveshaft to change it. #2 is the other one I could see that looked fine. The third is on the top, and I didn't take a pic. Since #1 was changed, and #2 looked fine, I am assuming #3 is the one that is causing my issues.

http://img.photobucket.com/albums/v3...3_115514-1.jpg

Here is a pic of #1 to try and show the cracking of it.

http://img.photobucket.com/albums/v3...203_115603.jpg

And here is a reference drawing showing all three. You need both #14's and #6:

http://img.photobucket.com/albums/v3...C/i2163391.gif


Here are the parts needed:

1 of these. $107.10
http://www.justforjeeps.com/fraxmobr.html

2 of these. $29.79 a piece
http://www.justforjeeps.com/fraxmois.html


When I change the other 2, I will take more pics of that part of the job as well.


Edit:

I replaced the other two last night, and here is a write up on how to do it...


To start off, remove all the bolts from the front drive shaft. There are 6 8mm bolts holding it to the front differential and another 6 holding it to the transfer case. Once the bolts are removed, it needs to be pulled out and set aside. I had to use a rubber mallet to help unseat it, as it was a little tough. A few taps of the mallet is all it took. I let it sit on top of the cross member instead of trying to wiggle it out (I honestly donít know if it will even come out unless the cross member is removed that is there. That was too much work, as it is fine sitting there.). Before you remove the drive shaft, make sure it is marked on the drive shaft and the joint so you know how it was positioned. If it is put in different, it might cause vibrations. Mine was already marked from the factory.

http://img.photobucket.com/albums/v3...209_142111.jpg

After the drive shaft is removed and set aside, start removing the nuts and bolts holding the bushings in their mounts. I would do the upper and side bushing before removing the mount on the front of the differential (if you remove the front mount first, it will allow the differential to hang down and put stress on the bolts for the other bushings, which will make it hard to remove the bolts). I also used a transmission jack under the differential to keep it from dropping until I was ready for it to drop.

Here is the rear of the drive shaft and how it was resting on the cross member:
http://img.photobucket.com/albums/v3...209_145714.jpg

And the front of the drive shaft. It was resting on the heat shield for the exhaust:
http://img.photobucket.com/albums/v3...209_145729.jpg

After the bolts from the bushings are removed, and the mount from the front of the differential is off, the entire assembly will be free to hang down and rotate to allow access to the bushings.

http://img.photobucket.com/albums/v3...209_155258.jpg

This was the hard part. The bushings are press fit into the housing, and mine we extremely difficult to remove. I ended up using an air chisel to remove it, but even using that was a pain. After the bushing is removed, the new one is press fit into the housing. I used a ball joint press, and it went pretty smooth.

When the new bushing(s) are in, reassembly is the reverse of removal (obviously). To get the nut on the bolt for the upper bushing, I had to set the nut in the socket and hold the wrench up against the bolt hole while using my other hand to slide the bolt in the hole. I had to do it this was because there was no way my hand would fit in the space to hold the nut. I also used the transmission jack to hold up the differential to help line everything up.

Tips:
*I did this on a frame lift and had tools/equipment that the Average Joeís garage wonít have (I was able to do this on the Navy base I am stationed at and they have lifts/tools for me to use). I know people have done this with a jack and jack stands in their garage, but there is no way I would do it that way after having so much trouble with getting the bushing out of the mount.

*The drive shaft will have to be rotated to get to all of them, but I also had to have the E Ėbrake on to be able to break the bolts loose, and tighten them when I put everything back together. So you will have to be able to get into the Jeep to put the E-brake on and off.

*The bolts for the drive shaft are 8mm. Having ratcheting box end wrenches will help a lot since the drive shaft kind of angles out around the bolts when it goes into the transfer case.

*The bolts/nuts for the bushings/front mount are 15mm for the bolt and 18mm for the nut (I believe. Donít shoot me if I was wrong, I did this last night and am trying to remember).

*Getting to the top bushingís nut/bolt is a complete pain in the ass. I had to take the wrench and slide it over the top of the differential on the driverís side and was just able to get it on the nut and hold it on by the end of the handle. For putting it back together, I had to put the socket on the end of my right index finger, and slide the wrench in the spot (without the socket on) and put the socket on the wrench while it was on top of the differential. I had to do it this way because once the new bushing was in, the differential did not hang down as low, so the few mmís of extra space I had before, was gone and that kept the wrench with the socket on from sliding up in there.

Here is a picture of how I had to put the wrench. The nut is directly in front of where the socket is:
http://img.photobucket.com/albums/v3...209_153657.jpg

Getting the bushing out was terrible. Mine was stuck like chuck. I hit it with a hammer and chisel at first and made little progress after about 20 minutes. Then I got an air chisel and that still took about 20 minutes to get it out completely.

Here is a before picture of the top bushing:
http://img.photobucket.com/albums/v3...209_155317.jpg
And an after:
http://img.photobucket.com/albums/v3...209_182950.jpg

This was the side bushing (wasnít bad at all):
http://img.photobucket.com/albums/v3...209_155309.jpg

2005JGC 12-03-2011 06:30 PM

Re: Differential pinion mount/bushing replacement
 
Good information... keep in mind its your bushing above the pinion that gets the most work and is ALWAYS the first to fail... from there its a matter of how long you let it ride and forced the others to carry the extra load. If I deal with a front end clunk I typically inspect what I can, there is like 1 angle you can get a small view of the mount above the pinion, typically more than enough to see its torn. I generally sell all of them while I am in there, I think my employer charges 3-5 hours to replace 1 and the extras are free so its preventative maintainence to save the customer some money down the road.

BTW the bushings are interesting, I have my way to do them, but not many people have what I have available to work with on their back in their driveway. Unless you have like a ball joint set at home I would not attempt this as you will likely not be able to get them out let alone in and will waste a bunch of time.

99formulam6 12-03-2011 06:36 PM

Re: Differential pinion mount/bushing replacement
 
Quote:

Originally Posted by 2005JGC (Post 526776)
Good information... keep in mind its your bushing above the pinion that gets the most work and is ALWAYS the first to fail... from there its a matter of how long you let it ride and forced the others to carry the extra load. If I deal with a front end clunk I typically inspect what I can, there is like 1 angle you can get a small view of the mount above the pinion, typically more than enough to see its torn. I generally sell all of them while I am in there, I think my employer charges 3-5 hours to replace 1 and the extras are free so its preventative maintainence to save the customer some money down the road.

BTW the bushings are interesting, I have my way to do them, but not many people have what I have available to work with on their back in their driveway. Unless you have like a ball joint set at home I would not attempt this as you will likely not be able to get them out let alone in and will waste a bunch of time.

I originally asked the dealer about doing in when I was in for an oil change, and they quoted like $130 for parts and around $270 for labor. It seemed low, so when I called to schedule the appointment, I asked him to verify that the quote was for all three. he had to call me back, and when he did, it jumped to over $200 for parts, and over $500 for labor. I asked a few local shops, and none had done the repair before, so none knew how to quote and the best I got was 'it will be atleast $350 for labor and could be more.'

That is just too much for me. I do the work on the base here, and they have like 10 lifts and pretty much any tool I could need.

Just to confirm, to remove the drive shaft, I only have to remove the small bolts that go around the perimeter and then it will just slide out, correct? I believe there were 6-8 of them.

2005JGC 12-04-2011 03:28 AM

Re: Differential pinion mount/bushing replacement
 
Nope just 4 15mm (bolt head) bolts and it separates... be sure to mark your driveshaft to companion flange orientation with a paint pen or something, better to be safe than sorry.

Make sure to unplug your solenoid before you swing it down or it will be out of the way enough you wont realize whats going on till something gives ;)

Also removing the front diff mount prior to the swing manuver allwes for slightly easier manuvering, iirc its not a problem to leave in though.

It boggled my mind when I found I was the ONLY person in the shop I worked in that realized you could just swing the differential down.

99formulam6 12-04-2011 10:06 AM

Re: Differential pinion mount/bushing replacement
 
hmm.. i will have to get under there and look again. I didn't see the 4 15mm bolts.

edit:
bolts #3 and #5 are the only ones I saw to remove the front drive shaft.


http://moparestore.trademotion.com/m...K/i2180898.gif

2005JGC 12-04-2011 03:17 PM

Re: Differential pinion mount/bushing replacement
 
I cannot remember EVER seeing that style of joint on the front driveshaft (front joint, I believe that is how the driveshaft bolts to the t-case) on a wk... Possibly on a 3.7l but I know for a fact every one I have done has been 4 15mm bolts. Again, not so say thats not the case across the board, but the compainion flange is flat unlike the big dish style compainion flange required for that style of joint.

99formulam6 12-04-2011 05:48 PM

Re: Differential pinion mount/bushing replacement
 
I just did the other bushings last night and just added the info/pics to the original post...

jlewissystem 02-19-2012 07:57 PM

Re: Differential pinion mount/bushing replacement
 
Hey Guys:
I need to replace 2 of these bushings - the side one is OK. I like to think i can do everything in my little garage, but this one has me thinking of actually going somewhere. Can anyone shed a little more experience on this? Maybe just buy the parts and take them somewhere? Sucks that there's actually labor involved here.....thanks!!!

99formulam6 02-19-2012 09:23 PM

Re: Differential pinion mount/bushing replacement
 
Honestly, it sucks. There is no other way to put it. However, if I have to do it again, I would still do it myself.

Escape 02-19-2012 10:49 PM

Re: Differential pinion mount/bushing replacement
 
Excellent info.

This needs to be put in the HOW TO section!

Plus I need to do this also.

tri0829 02-19-2012 11:20 PM

Re: Differential pinion mount/bushing replacement
 
My rear differential is going the dealer claims around $1500 for me they said they have to rebuild the whole thing but at the moment it is okay just loud,
would this cause a noise while driving too, i had the clunk but now its turned to a noise hard to describe what it sounds like sort of a medium pitched friction noise

99formulam6 02-19-2012 11:27 PM

Re: Differential pinion mount/bushing replacement
 
Your rear differential? This only applies to the front, as the rear doesn't have these bushings.


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