Truck cranks and sounds fine. When put in reverse it idols itself up. But when I drop it down to drive the truck cuts off. No codes or nothing.

 

Have you modified the transmission? "Built" autos have been known to do this. I am guessing that once it gets warmed up it does everything fine.

 

Just a few upgrades in the trans. But it has never done this. And no it is worst when it gets hot.

 

You might want to take it to get it looked at.

 

Yeah this one has got me.

 

Have you done any kind of valve body upgrades? Befor my auto went bad, it would shift up only if I manually did so. That being said as far as down shifting went it would go all the way down to first then lockup in first and kill the engine if I held the break. Try slipping into drive without holding the brake.?