EDM broken diff pin bolt

[demian5]

So in an OG 93k 12 bolt rear diff, the bolt broke off at near the bottom of the threads. Drilling was unsuccessful, going to take to a broken tap guy to EDM out. I thought i'd start a post as I am sure this is a normal thing that happens.

[LockDoc]

Originally Posted by demian5

So in an OG 93k 12 bolt rear diff, the bolt broke off at near the bottom of the threads. Drilling was unsuccessful, going to take to a broken tap guy to EDM out. I thought i'd start a post as I am sure this is a normal thing that happens.

Did you buy the drill kit or just wing it? I bought the kit and have had really good luck with it. I didn't buy it from here but this is the type I bought....

http://www.freedomracing.com/dpk-01-...SABEgLnpfD_BwE

LockDoc

[demian5]

Originally Posted by LockDoc

Did you buy the drill kit or just wing it? I bought the kit and have had really good luck with it. I didn't buy it from here but this is the type I bought....

http://www.freedomracing.com/dpk-01-...SABEgLnpfD_BwE

LockDoc

I could make one on my lathe, but no I didn't try it. Whats the thread pitch?

[LockDoc]

Originally Posted by demian5

I could make one on my lathe, but no I didn't try it. Whats the thread pitch?

Thread pitch of what?

LockDoc

[demian5]

Originally Posted by LockDoc

Thread pitch of what?

LockDoc

Of the bolt that goes into the diff. The one that broke.

[LockDoc]

Originally Posted by demian5

Of the bolt that goes into the diff. The one that broke.

I think it is 5/16-18.

Don't you have the one that you took out?

LockDoc

[Ol Blue K20]

I've had pretty good luck by just using left-handed drill bits. It usually catches and spins them out.

[toolboxchev]

Originally Posted by Ol Blue K20

I've had pretty good luck by just using left-handed drill bits. It usually catches and spins them out.

I am putting that one in my tool box!

[Ol Blue K20]

Originally Posted by toolboxchev

I am putting that one in my tool box!

Good idea, I have a left-handed drill index up to 1/2 inch by 64ths. It comes in handy quite often.

[Killer Bee]

some related discussion here recently, some methods may be useful..

broke bolt in end of crank

I have some experience hiring EDM work.. all larger benchtop machines, have not seen a portable in action personally..

most memorable; had a tech break a bolt in an expensive german hydrostat pump housing belonging to a local offshore platform.. not only expensive, extremely long lead times and customer would not have been happy.. $75 [20 years ago] local machine shop blasted it out of the housing, clean as a whistle, saved out butts!