Rear differential with a broken bolt

[jeepham]

Hello Everyone,

Just bought a great 1996 JGC LTD V8 4x4 and took it to the mechanic for a noise coming from the right rear. The mechanic determined that the wheel bearing is causing it, but when he tried to release the right rear axle, he found a broken bolt in the differential mechanism. Here is the description in his own words: "Retaining bolt that secures spider gear spacer shaft is broken". He didn't want to try to fix it, telling me that I should take it to a rear end specialist.

My question is: how much work is it to replace that bolt, and how much money am I going to have to spend on the repair (ballpark).

Being an electronics technician and a hands-on guy, I would rate my mechanical capabilities as good - is this something I would be able to do myself?

Thank you,

Ervin

[nick0750]

you really should take it to a dealer or a rear end specialist there is a lot of technical work involved in rebuilding a rear axle, tolerances and shimming and
pre load and spacing it can get pretty expesive labor wise parts are not too bad.

[dksob81]

well if it's just the pin for the Mate shaft you could easily do this yourself, but because it's the rear axle it becomes more complicated..

The mate shaft has a lock pin that just holds the mate shaft in place there really no tension on it, I have no idea how it would break, but anyways, this lockpin just slides in, you just have to use a drift (or suitable punch, centerpunch, etc...) to tab it out and then put a new one in. Some mate shafts have a lock screw which uses a hex bolt that holds it in place, if the head broke then this will require a bit more skill, using am ez out or drilling and tapping.

Either way on the rear axle this job becomes a bit more complicated, because you need to remove the lock pin/screw to remove the axleshafts to remove the diff case. the reason, on rear axles that use C-Clips you need to remove the lock pin/screw and pinion gear mate shaft to slide the axles in far enough to remove the C-Clips.

[xj31]

Usually the bolt has no tension on it after it breaks and you can take something like a pick and unscrew the bolt.If this doesn't work,I punch the pin out with an air hammer.This will break the bolt and then you can get the case out and work on it the bench.

[Ray H]

If its the lock screw that broke off, Im not sure how to get that out. I would say the carrier is going to have to come out and the remains of the screw will have to either be drilled out or you may be able to get a small easy-out in it and back it out. The catch is that you cant remove the carrier until that screw is out or at least the MATE SHAFT that the screw holds in place is out. Either way, I dont know what your relationship is with this mechanic but these screws dont just break off and they dont corrode or get "stuck", someone had to torque it too much and break it either while installing it or turning it the wrong way to remove it.
This is something you can do if you are moderately mechanically inclined and are detail oriented.You must mark everything including bearing caps, shims and replace them exactly how they came out. The special tools you will need to remove and reinstall the carrier, besides a nice set of sockets, are a ft/lbs torque wrench, rubber mallet, a couple pieces of 2X4, a crowbar, some way to raise the Jeep so you have room to work under it and whatever you need to remove the screw. you will also need a big punch or steel rod or something to beat the mate shaft out of the carrier. this is the part Im not sure about as Ive never had to do this. I do know that the mate shaft has to come out to get the carrier out and I cant see how you can get the screw out without removing the carrier.

[JDPascal]

Already a lot of good stuff posted on here.

This may depend on whether or not the bolt has been removed before.

With the head broken off, there should be no tension on the threads but most of the lock bolts have thread lock applied from the factory. Use a little heat to release the locking compound and try a left hand drill bit.
http://www.mytoolstore.com/hanson/hanson.html

It may drag the bolt back out of the hold as you drill.

That is if the spider gears haven't siezed onto the spider shaft and started to sheer the pin on the end of the lock bolt. If that is the case, all you can do is drive the spider shaft out with a BFH or a air hammer and hope for the best.

JD

[old_lamanna]

Originally Posted by xj31

Usually the bolt has no tension on it after it breaks and you can take something like a pick and unscrew the bolt.If this doesn't work,I punch the pin out with an air hammer.This will break the bolt and then you can get the case out and work on it the bench.

There is a tool for this made by fabbri associates. you can get it on their website or from matco, or even ebay. Worked for me in 15 min. No fuss, no damage.

[SteveB05]

a small "easy out" or bolt extractor and the proper drill bit and it will come right out. These retainers are commonly broken and can be had at the dealer for under 10 bucks.