So seems like when the truck leaves off line it launches and then falls on face and is in high gear, is something tellin it to do that. Just leaving it in 3rd as I should. Don’t think the tires are slipping causing it either, ideas

 

I'm sorry... Just to clarify; are you stating that the vehicle seems to launch in first gear, but immediately shift to third gear?

Or the vehicle launches in third gear?

When this happens; have you tried moving the gear selector down to second gear or first gear positions?

Or moving the gear selector up to fourth gear position?

Does the vehicle shift normally through the gear ranges when driving the vehicle normally?

 

Almost sounds like torque management.

Or the tires spin causing rpm to go up and hit the shift point, then it upshifts and doesn't have enough power to keep pulling in the gear it upshifted to. I'd shift it manually and see what happens.

Sounds like torque management, good thing it's there because it makes racing fun doesn't it....