Chevrolet Repair: Broken bell housings, broken bell, bell housings

Question
90 S10 EL 2.5 4 cly 5 speed

I have had to replace several cracked bell housings. I'm on my forth one and this time the starter cracked too. I have replaced the motor & transmission mounts and the motor mounts appear to be bad again. (Cheap parts?)

What is causing the bell housing to crack and how do I fix it.  

Answer
hmm could be cheap parts but something is causing it to break, what kinda breaks are they clean or does it looked tourqued? to much tourque might do it. hmmm hard to say with out seeing it.  as for fixing it, replacement is the only thing i can see right now, i dont know if there is a glue or welding that would help. wish i could be of more assitance. keep me posted.