Pulled out my trans to service the clutch and snapped 2 of 4 bolts in the process (see photos below). Having surfed around on TGO, I see that unfortunately this is a common occurrence . Would’ve been nice if GM put an access hole in the frame to at least allow you to squirt some lube or penetrant on the bolts, but I’m guessing that would weaken that cross-section, so they didn’t.

At any rate, has anyone successfully drilled holes in these to remove the broken pieces? I’ve read several horror stories of folks breaking their EZ-outs and then cutting holes from the floorboards, etc. I’ve never used an EZ out, but apparently they’re brittle and prone to breaking. Someone suggested hammering a notch and using a screwdriver, but honesty, I can’t see that working here given the torque needed. Maybe that works after much heat and penetrant applied??

Was thinking to start with a small drill bit, then gradually work up a few sizes and apply heat and penetrant along the way. Just not sure if you then follow with an extractor to get the rest out, or if you can use a tap to do that.

Any advice and photos would be appreciated. Thanks!

 

That sucks. Drilling upside down sucks because your shirtsleeves will press the hot metal shavings against your forearm.

Just start drilling small and then progressively go bigger until the threads are exposed on one side (you'll never get it 100% dead center). Then you can pick the remnants of the broken bolt out. Chase it when your done and it should be all good.

Good luck!

 

I've used the EZ-Out & it has worked great. I've also used the EZ-Out & turned a thermostat replacement job into a intake manifold base (TPI) replacement job. That turned it into a "$1000 thermostat" after the towing & having to have a shop do the manifold replacement.

I've also done what you suggested...Stepping up in drill bit sizes & careful not to hit the receiving parts threads then just a tap to clean the thread pieces out. But that was an intake so I was able to get up on top pressing down, not cramped under a car & drilling upwards.

 

Considering the fact that the bolts aren't rotten, I think you could get it out with an EZ-out. Yes, the EZ-outs are brittle, but I have used them successfully in the past. I would lube the crap out of those bolts and let them sit and soak. Center punch the middle of the bolts to give the drill bit a place to start. Once you've got the center mark made, give it a couple more good whacks. You want to start to loosen up those threads. This is a good thing to remember when loosening fasteners. Especially Phillips screws, I always give them a little tap before I start trying to remove them...they always always strip.

eseibel67's idea will work too if you're not wanting to use the EZ-out.

 

reverse direction (counterclock wise) drill bits......step up from small to large