Originally Posted by Mechanic@tdpud
Been in the automotive repair industry for 31 years, My son has my old 72 el camino donw in L.A. he was rear ended shortly after the 700r4 failed, a trans shop down there fixed it under the insurance. and shortly after he started complaining of an engine knocking under load, just tonight the gear reduction starter started not meshing with the flexplate. of course he wants me to diagnose the problem over his cell phone. Im thinking it is a Cracked Flexplate. any other explaination that may come to mind ?
1st thing id do is unbolt the conveter from the flexplate and see if the flexplate sounds "tinny" when u tap on it with a hammer(dont hit the teeth)., if it sounds dense and solid, its not the flexplate. other than that, while the converter is unbolted, run the engine and see if the knocking is still there.
if so, the rear-ender may have killed the rear main bearing in the motor. (its the journal that that controls endplay)
also, like doc said, with the engine off, see how much, if any, the crank does go back and forth..
ill disreguard docs statement about us tranny guys.. we cant all be good tranny men