My 450 dozer is a early 70's and seems to run fine but last week I was pushing dirt and trees and had some problems. The dozer shut down like the motor locked up. I tried to start it and it was very tight like over compression. The only clues I have is that after it sits, it will start and run till the pressure on the torque converter builds, then shuts down again. I also notice a bit of smoke coming under the torque converter. It does not smell like clutch or electrical smoke. I don't know if it has a clutch on the flywheel but everything seems to be turning through the sight holes on both sides. The driveline does turn and turns by hand when not running. I can not get it to move yet. Hydraulic working fine and I've checked and filled all the fluids. Need some help.