now what do I do ...
 

well the unthinkable happened. I was trying to get that damn bolt/pin out of the rear dif so I could slide the pin out to get the shafts out so I could put in new rear caliper mounting plates. Well, I can't get it out thanks to the bolt head stripping. I tried to tack weld a nut over the existing nut but thats not working too well right now.

Any idea how to best get it out or how I might proceed?

Thanks,

Jorge

Heat the diff up around the bolt a little? Those little bolts can cause many headaches. I've even had to go so far as to cut the spider pin out with a torch. Good luck!

-Kopp

I just want to be sure I am on the same page as you.
there is only one bolt that we are talking about and it runs parallel with the axle. I remembered you said 5/16 head an only one in there matched it but just to be sure.

Also did you head it up with an OA torch or it doesnt need that much heat. I have a torch I use on copper as well as an OA torch.

Heating the carrier housing (not the bolt) should improve your situation, it will ixpand the female threads (but you still have to grab the bolt head somehow). I know for a fact the FoMoCo 8.8 uses a metric bolt (8mm I recall - too damn small in any event). Also use an 8-point wrench and not a 12 point (moot point now that the head is stripped). Best of luck - let us know how things turn out.

I've never actually had this exact problem Jorge. I've had that pin end of the bolt break off a few times and once I could not get it out no matter what. That is the time I had to cut the spider pin. I'd probably just try a small propane torch like you would use to do plumbing work with like the one you mentioned.

Follow Bill's advice (except I think he meant 6-point not 8- ;) ) and hope you're lucky.

Yes Kopp - I meant 6 point. It was getting late and I was tired of watching cars go flat out w/o lifting and around in a circle 200+ times....

thanks for the help guys. That damn thing is not coming out. I have tried a few times welding another nut on top of it but I cant get enough penetration. All I wanted to do was get those new caliper brakets on and change the wheel bearings and now .. nothing....

Any suggestion that may have been overlooked?

Can I just pull out the center section by removing the four bolts and take it some place?
Maybe now is a good time to have the rear end worked on....

Can't pull the center section without removing the axles. Can't remove the axles without pulling the spider pin. Can't remove the spider pin without removing the lock bolt. You're in a tough spot. Maybe try to break it loose with a chisel and hammer? I take it the heat trick didn't help? I don't have much else to offer Jorge. You're in a tough spot.

-Kopp

There are some new sockets out made by, I believe Snap On, that have "teeth" in them made for the exact problem you are having... I have not personally seen them but a buddy of mine was telling me about them last week. He said the "tool guy" that gave him the demonstration took out a bolt that had the head rounded into almost a perfect circle...

Is the rear end out of the car? If not, maybe try taking the entire rear out of it so you can get a good angle to weld the nut onto head.

I have run into the same problem before with an engine mount bolt. I took a grinder and ground the bolt head smaller then drilled out a nut and drove it onto the head. I then welded it to the bolt as you described. The heat from the welder broke loose the factory thread locker.

Thread Locker
 

As I recall, that pin does have factory thread locker on it, that combined with a very small bolt head, combined with a 12 pt wrench is disaster in the making.

I'd recommend locking onto the bolt head tightly with a pair of vise grips. Then before you try to turn it, heat the hell out of the carrier in that area with an oxy aceteline torch. I don't think propane will do anything, the iron is too thick and the oil impregnation makes it hard to get alot of heat into it. Mapp gas might work but I recommend OxAc. Get it glowing before you try to turn the bolt.

The suggestion a couple of lines above about the special sockets is a good one. The socket on the inside is like a cone with teeth, it does need some downward force to work though.

Mark