Re: Stripped my crankarm.
One of the pedals (Can't remember which side) is reverse threaded to prevent it from coming off while pedaling. This is probably why you had a problem and is probably the affected side. You can try reverse threading it back in and see if it still holds. If it does, don't ever take it out again. If this doesn't work you will have to replace the crank arm which is both sides on a one piece crank arm or the affected side on a three piece crank arm.