Originally Posted by
FBinNY
Odds are that your BB is fine, but the crank may be toast. You probably need a new crank arm, but the steel spindle of the BB is most probably fine.
That happens often enough that, if you're not fussy about having a perfect match, a local bike shop may have a replacement in stock. That's about a $20.00 part. There are 2 things to look for:
1. The crank arm length will be stamped on the inside near the pedal hole. It'll be something like 172.5 or 175. Make sure that you get a match.
2. There's squares and there's diamonds. Make sure that your new crankarm matches what's on the other side.
The torque spec for crankarms is generally around 30 lb/ft. That's more than you're going to get using a six inch long allen key. Imagine a 30 pound weight hanging off the end of a foot long wrench. Tighten it that much.