Got it fixed. It was the seat switch. Previous owner had disconnected it. How did he cut grass? The mower had not been very well taken care of. I guess he sold it because he couldn't fix it. It runs great now and the transmission also works fine now.
JD D105. Just finished R & R the RT400 transmission to install a new secondary pulley. Mower wouldn't hardly move because the pully was frozen up. Wouldn't grab the belt to enable the axles to turn. Now, the mower runs and drives like it should but I can't get the cutting blades to engage...