I have a 2001 chevy silverado 1500 and was driving when all of a sudden a violent bang and then loud grinding sound from directly under cab. Towed in neutral at 10mph and was clicking the whole way. Rolls forwards but tires are locked up when u try to push or tow it backwards. Transmission?

 

Listen for a heavy clunk when shifting from neutral to reverse and back again. Check the transmission cross member mount (rubber dampers) for excessive wear or splits. A noticeable vibration in the chassis frame during the heavy clunk will point more toward a defective transmission mount rather than a torque converter problem.

 

Did what u said and everything pointed to tranny had a guy look at it it was tranny lookin at $2300 to fix. Thanks for the help!