On behalf of a friend I've been asked if anyone has any Info on getting out a broken differential pinion shaft lock bolt/screw on a 1989 F-150 4 wheel drive. It sounds like it's broken off deep in. Thanks for any help.

 

I've personally never gotten them out per se, but depending on where it is snapped off, I've been able to forcibly drive/beat/angrily hammer the cross pin out. Then replace the cross pin and retaining bolt. But that doesn't always work.

 

Torch and a new carrier

 

I got mine out. Used a cut off wheel on a dremel down each side of the cross pin until the bolt was cut almost completely through. Then just drive the cross pin. Only reason I didn't cut the bolt completely through was because the cut off wheel was to small. Yes the cut off wheel will get into the carrier some. It doesn't hurt anything. I will try to find a picture and post it. The only other option is a kit they sell that has hit and miss results, I think it was designed for a gm, it's just to hard to get to an 8.8. Or as Brad and mudsport said, a new carrier and torch or bfh. The bfh risk housing damage, but is unlikely, but very likely to have carrier damage. A torch promises a ruined carrier but no housing damage.

 

This should help explain, the bolt is only threaded on the head end, so after you get the cross pin shaft out, remove carrier and drill out what's left of threads(if any, depending on where your bolt broke) then if the other side doesn't just fall out, use a magnet or pick. I did not get into my carrier this much. Wish I had took a picture of mine, but you get the idea. If you do this, make sure your right cut looks like the left cut in the pics. This guy actually cut some of his threads in the carrier.