Fix it or let it ride? (Trnsmsn bolt head broke)

So a few weeks ago I was going to remove the transmission pan from my 08 SR5 automatic. Well about ten bolts in, I had one snap off. I think the owner before me had dropped it because there is a rubber gasket on there and everything I've read says that Toyota uses fipg at the factory. I figure he over-tourqued them. So anyways, I immediately threaded back in the other bolts, refilled the pan (correctly, putting it in AT Temp check mode). I let my mechanic buddy take it home to see if he could extract it without removing the pan. There wasn't any thread sticking out that you could grab with some vise grips, so he used an extractor tool. Used a die to tap it in the center and began trying to extract. The damn tip of the extractor broke!

I was out of town on leave, so I told him to just use some rtv around the area and we would look at it when I got home.

It hasn't leaked at all. You know even after you take all 20 bolts out you still have to use a rubber mallet to break the seal, and both bolts on either side of the broken one are good and torqued down to spec. I read on here where one guy crawled under and found he had a broken bolt head for who knows how long.

My wife and I were just talking about going over to George Washington and Jefferson National Forrests for son OHV trails that we like. I suddenly became nervous about that damn bolt and being on the trail.

So.

Long winded I know, but anyone got any advice? I have all of the necessary parts to remove the pan and try to see if hopefully we can get it with some vice grips (granted there is something to grab after we drop the pan). I have a new fel pro gasket, 20 new bolts from Toyota and some Toyota WS ATF to refill the pan with.

He says if we can't get it with grips, then we could drill it out and re tap. He's an ASE certified mechanic with a decade of experience behind him and I trust him.

What do you guys and girls think?

 

It's possible with a good quality bit, just try not to screw up your threads

 

You said that the tip of the extractor broke off. Is that tip still in the bolt? If it is you are going to have a hell of a time drilling it.

If the tip of the extractor is not in the broken bolt. I would try a left hand drill bit running the drill in reverse. This could and usually does back out the broken bolt. It usually works really well on small bolts such as these.