'99 F-350 7.3Lturbo 4x4 dually dump 4 sp a.o.d. tranny ...in cold weather (0 or so)i plug it in ...fine start up but if i dont let it warm up and just try to get in and go i can push the accelerator to the floor and the truck will not move...or accelerate at all...when it warms up though LOOK OUT...i plow tons of snow with it no problem ...whats up with this? is this common with cold trannys in these? first time diesel owner...zap!

 

Theres a combination of things going on. Even though you plug the truck in, its not heating up the transmission fluid. It works by heating the coolant through the water jackets which helps to heat the oil as well. Cold trans fluid does not flow well till it warms up like you speculated. The other thing is your truck has whats called an EBPV (exhaust back pressure valve). This valve is put on to put a load on the engine. When the engine oil temp is cold it closes the valve to help speed up the warmup time. If the valve is closed the turbo can't push exhaust gases past it and you get low boost and power. It should turn off while driving, but are known to fail and close when they shouldn't. Alot of people in cold climates have remove or unplugged the valve and have had no ill effects, just slightly longer warmup periods.