marko69

Any idea's on how to remove this broken transmission pan bolt?
I can't get to it from the side's to use a pair of vise grips,
I ordered this from amazon but it shows 6 - 12mm and I measure the stud
as 5.7mm, I ordered it any.

Amazon

Amazon

Tom Manning

First - gently heat around the bolt, see if it shifts. I think that would do it.
If not, MIG weld a nut onto the bolt.

streborx

Do you know why it snapped off? Rust/corrosion on threads, cross-threaded, previously over-torqued -- makes a difference when devising an extraction method.

marko69

Would be nice if I had a mig welder.
I was in a hurry and daydreaming and had my torque wrench set to the drain plug torque of 20 Nm instead of 4 Nm.

as.thompson

Can you cut a slot in the broken face with a dremel tool or similar and use a screw driver to remove it as if it were a machins screw?

cdk4219

Aren’t they aluminum bolts?

Tom Manning

Looks like they are. In that case just carefully cut it flush then drill it out.

marko69

If that amazon tool doesn't work, which it probably won't since there isn't much to grab onto, yes, I think drilling it out will be my only option.

streborx

Drilling it out might damage the internal threads and leave you with an even bigger problem. Take your photo and one other identical bolt to a local auto store. People break bolts all the time, and auto stores carry extraction tools for this reason. There are two common extractor types. One grips the bolt around its diameter and tightens its hold as you turn it ccw to remove it. The other type requires a small hole to be drilled in the broken bolt's center, and an extraction pin is inserted into the hole, and forces itself in tight as it's turned ccw. The first type of extractor requires enough exposed bolt to grip. The second type requires the exposed broken bolt surface to be filed down flat so it can be punched for the drill bit point. Either way, take your time and don't rush. It's easy to turn this type of difficult problem into an impossible one.

I have several sets and varieties of bolt extractors in my tool box -- you're not the only one who has sheared a bolt!

(While at the auto store, don't forget to buy a bolt to replace the broken one.)

elMacko

I can see that there is a good portion out. Apply plenty of rust removing spray. Cut a slot with a dremel tool abrasive wheel and try a flat screwdriver gently turning it in both direction! The screw is too small to drill a hole in the center, then the extracting tool will be too small to apply the necessary torque. If nothing of this works, grind the exposed face flat, drill a hole at the center with a 1/8" drill bit, then progress to a 3/16". This bolt is 6 mm, so the 3/16 should remove and it is the drilled hole for a 1/4-20 bolt, which you can re-tap on the same hole!

marko69

Guys, this is gunna be very anticlimactic, but I tried a small pair of vise grips to get at it vertically. With the force to break the bolt head off, I thought that stud would be in there pretty darn tight. Apparently it was not. I was able to unscrew the stud in about 1 minute. Thanks for all your replies and suggestions.

as.thompson

Glad that you were successful. Time now to relax...

streborx

Glad you didn't have to do the drill.

gaazmon