I have a 2001 duramax 2500. Bought it used. Guys said glow plugs bad and some fuel issue. I replaced plugs and batteries tried to start and it turned over fine there was a spot where the starter would grind. I pulled the start and saw the teeth chewed up on the flywheel. I ordered a new flywheel. It sat for a couple months. I pulled the transmission and was ready access the bolts for the torque converter. When I tried to spin the flywheel to line the bolts up to access them from the starter hole the motor went turn. I tried bars, wrenches, a socket on the crankshaft etc. Any ideas?