So, what did you do today?

[Casey_SS]

The bolt broke off below the face of the diff, so there is no way I can weld anything unfortunately...

Craig,
I'll certainly use some heat on the housing before I try and drill/spin the bolt out.

Is there loctite on the bolt? If so, you'll want to heat the bolt itself to loosen that stuff up. Probably also want to heat the housing around the bolt to equalize whatever thermal expansion you get from heating the bolt. Without the head, there shouldn't be any torque on the threads aside from any loctite resistance. Maybe try welding the tip of a smaller bolt to it and use that as a handle to spin it out. If it's really down in there, just keep adding tiny spot welds in the center of the bolt until you build it out enough to get to it without accidentally welding it to the case.

[Supercharged111]

My cousin welds washers down there when he needs to get a stack going.

[edrock96GT]

What Casey said. My shop dispatcher has gotten really good at spot welding enough of a bead that you can build it back up past the surface and then weld a nut to it. We've broken a few exhaust bolts on older cars in our shop.

[dtanker65]

Grind a small divot in the center of the broken bolt with a small Dremel carbide burr so the drill starts centered. Drill a shallow hole with a cobalt bit for an easy out (the stubby snap on easy outs are best) If you use a hardware store easy out, grind the tip off until it fits the shallow hole. You don't want to break the easy out or drill off in the bolt. Once you have good bite with the easy out, heat the housing until the bolt unscrews with light torque.

[Trublu]

Grind a small divot in the center of the broken bolt with a small Dremel carbide burr so the drill starts centered. Drill a shallow hole with a cobalt bit for an easy out (the stubby snap on easy outs are best) If you use a hardware store easy out, grind the tip off until it fits the shallow hole. You don't want to break the easy out or drill off in the bolt. Once you have good bite with the easy out, heat the housing until the bolt unscrews with light torque.

A good wack from a hammer to the easy out never hurt anything either

[marshall_mosty]

I talked to one of the old guys in our proto machine shop. He gave me a cobalt bit and a higher quality center drill. He also advised to hammer the end of the easy out while I'm turning it, so matches your suggestion Dennis. Thanks for everyone's feedback!!

[dtanker65]

I talked to one of the old guys in our proto machine shop. He gave me a cobalt bit and a higher quality center drill. He also advised to hammer the end of the easy out while I'm turning it, so matches your suggestion Dennis. Thanks for everyone's feedback!!

Don't forget the heat, a Home Depot Mapp torch is good for this.

[marshall_mosty]

Don't forget the heat, a Home Depot Mapp torch is good for this.

Bought a torch head, so should be in good shape.

[marshall_mosty]

Bolt removed...

Started off with the cobalt RH bit with a fair amount of cutting gel. Got down about 1/2" and switched to a LH drill bit. Added a bit of heat to the housing and when the LH bit dug in, the bolt turned right out.

The OE helicoil looked pretty jacked, so I bought a helicoil kit to re-drill and tap the hole and go back with a fresh helicoil.


Thanks to everyone for the suggestions.

[marshall_mosty]

Trina just walked across the stage at Texas Tech to get her BSN degree!! So proud of her grit and desire to go back to school at 41, with three kids (four if you count me, which I would), work a job, and keep our house running. She's my champion!