How is your clutch doing? any better
Branson advised my dealer that they had seen the problem before and recommended a replacement of the Electronic Control Module for the transmission. The part has arrived and the tractor is in the shop now. I am a little skeptical since the problem only starts after the motor/transmission is hot. The transmission works smooth as butter when first started and gets progressively worse as the engine/transmission gets warmer. I am not sure if the heat affects the ECM, but I guess it could.
To recap, when hot, the transmission jerks hard when engaging, whether with the clutch (potentiometer switch) or shuttle shifting. After the initial jerk, the transmission then smoothly engages and begins movement in the direction selected. This jerking is hard enough to slip all four tires on the dirt about 6 inches when running the engine at the recommended 1800-2100 rpm. The jerking occurs with the same intensity whether going forward or reverse. Replacing the potentiometer clutch switch did not help the problem.
I will post the result of the ECM change-out.