Stipped two bolts -- now what?

So, I was replacing a couple gaskets where the transfer case shifter meets the transfer case (4 bolts). I was torquing them to the specified torque using a torque wrench, but two of the bolts stripped. I'm guessing I was torquing at an odd angle and the torque wrench wouldn't click, or someone had previously stripped the bolts and that was the cause of my leak. In any case, how do I repair the differential which is now stripped out? Also one of the bolt heads actually snapped after stripping the differential, which sucks. I'm guessing I can get the stripped bolt out with a vice grips but we'll see. The bolt is: 7t (marking on head) 8mm diameter 25mm length 1.25mm pitch hex head. Should I tap new threads? If so what diameter should I use? It looks like Toyota bolts go from 8mm to 10mm, not sure if I can go up to 10mm.

 

The TC is aluminum, so it doesn't take much to over-torque.
Should have been 13 ft-lbs (according to the FSM).

 

I had it set a hair under 20 ... Maybe I stripped it myself, but in any case, how can I fix it?

 

Wish I could help you, but I've never had to deal with this.
Try googling. There's likely some youtube videos for details on this repair.

 

I ordered 12mm long 8mm diameter 1.25mm pitch helicoils (it's an 8mm diameter bolt, so that follows the 1.5x rule). Hopefully this works alright I preferred the idea of drilling it out and tapping it with real threads, but I'd rather use the same size bolts if I can help it.

 

I think on something that is effectively just an oil seal your repair will be more than adequate.

 

One other question: if I plug up the large hole the shifter goes in, will the metal shavings from drilling fall into the transfer case or not? Basically I'm wondering if the bolt holes end in metal or the air of the transfer case?

 

Dry threads? If using anti-seize or if there's any moisture/oil your torque measurements are gone. The paperwork with your torque wrench should warn you only count on it for dry clean threads.

 

There is a helicoil alternative called Timeserts :
https://www.amazon.com/TIME-SERT-Metric-Thread-Repair-1812/dp/B001JK44LG