maybe since the bolt broke off its going to be pretty stuck in there i would recoment using some pb blaster or soem sort of wd-40 product and maybe try to heat up the area around the bolt were the treads are to get it to be able to move and then e-z all it out ... and if that doenst work then the only other think i can think of to do is drill the intire bolt out and retap the tranny and have to use a slightly bigger bolt. which should be the last resort

scarponze