Timemaster 30 traction

I picked up a 2013 Timemaster for cheap. After fixing all the other issues I can't get the self propel to work. Installed a new drive belt and traction cable. If I push the PP handle all the way down and then grab the cable and pull hard it will start slowly and then pull like a mule. I've owned and worked on these mowers before and never had anything like this. On other mowers I'd replace the drive belt and or cable and it was good to go. Cable is adjusted properly and both springs are good and the pinion gears & wheel teeth are good. If you've ever run into this and fixed it I'd appreciate your help.

I ended up breaking the cast alloy actuator piece on the trans that the cable attaches to... so bought a new transmission. Installed it and it works better but not like it should. New cable, new drive belt, new transmission. All other parts in good condition. You'd think it would be good to go.