Broken trans bolt, best drill bit?

[b00stedtalon2]

So on my girls car, the 14mm bolt that goes to the block for the trans is broken. It is the one that is right next to the front motor mount bracket. What would be the best drill bit to get through this sucker? We plan on running a bolt/nut once the broken one is drilled out.

 

[soulweaver]

DONT DRILL IT OUT. Go to advanced auto or some auto parts store and get an extractor bit. Crank that up in the old broken bold and twist it out. It will save your threads and keep you from having to tap a new hole.

 

[the_mork]

I would start with a 3/16 cobalt bit then use a 1/4 bit to reem it out and just keep stepping up until you can get a good size (in comparison to the bolt) EZout into it.

 

[soulweaver]

I would start with a 3/16 cobalt bit then use a 1/4 bit to reem it out and just keep stepping up until you can get a good size (in comparison to the bolt) EZout into it.

Thats a good idea but then you have to do a lot more work. Just use a EZ out (aka extractor) then use the tap to rethread the hole. Just use the tap that is the exact size of the hole.

 

[Defiant]

Good god, people. It's not a rocket to the moon.