Ok so I'm back in the same spot.
This truck is still giving the same symptom as last time. When I plug the motor makes a horrible noise (metal on metal) and stops the truck instantly.
the drive motor upper bearing, drive motor lower bearing on the pinion shaft and the upper drive unit bearing at the base of the pinion shaft have all been replaced, new shims and all, including the base plate.
When I swap out motors from one truck to another the problem stays with this truck,
The plugging diodes have all been changed out and aside from changing out the oscillator card I'm at a loss any ideas?