I have a'99 Chevy 6.5 turbodiesel. It has a 4L80E transmission. Started truck, slipped into drive gear, released foot from brake petal, started to roll forward, and then the back end locked up and the truck skidded to a stop. Transmission will shifted through all gears with no problem, just does not go into gear. Fluid is full and clean. I have not had an issue with the transmission until now. So, I have no back ground with this issue. Starting from scratch... Is seems that communication from the shift lever to the transmission is being interrupted. Has anybody had like symptoms, and what would be the remedy?