Built 6spd Allison by Mike L. Truck runs flawless shifting through gears cold or warm. Doesn't hesitate to go into gear, it just slams into reverse or drive after the truck has reached operating temp. More going into drive than reverse. It feels like the drive train is moving one way and then suddenly has to go the other. When I put it into drive the truck will lurch forward ever so slightly. You can clearly hear a loud bang when going between reverse and drive. I always am at a standstill and pause in neutral. Stock TCM. EFI tuned by Idaho rob on a DSP5. Thoughts?