First let me say I am no diesel expert..

I have a 1999 3/4 ton -automatic trans. approx 78k miles. I recently started experincing hesitation-no power when first driving the vehicle especially when engine is cold.

Start up - notice some smoking that I haven't had before. Press on the acceleartor an it seems to bog down, shift to low or second does not seem to help. After serveral miles drives normal. Someone mentioned a govenor to transmission ??? may be an issue...

The only thing that I can think of that may have caused a possible transmission problem is that several months ago I was pulling a loaded horse trailer up and down steep grades in the mountains...I took it out of OD going up and dropped it down in 1st or 2nd going down the mountain to save on the brakes.

Do I take it to a Transmission specialist or a engines specialist or BOTH