ok so let me start by saying my car has been through a few motor swaps and the trans has been bolted up to a few motors. ok now the setup im running now has been in the car for quite a while. (a few years) recently i was riding down the rode and heard a loud knockin noise. thinking it was a rod knock i pulled it into my shop and put it in the air and found that it was the flexplate. so i rotated the flexplate and found that one of the bolts had come out and was missing. i installed a new one and now they all keep coming loose. and i have started to develop a crack by one of the bolt holes. any ideas what may have cause all of this to happen. the trans was rebuilt about two yearts ago and has a shift kit in it. the crank was replaced at the same time.

 

no ideas?