I have a friend of mine that has a 2001 2500 4X4 47re 56000 miles and a bully dog box of some kind 60 hp I think.

The truck developed a shifting problem over the last week.
The trans will hang in first gear untill you let off the throttle.
If you let off it will shift. If you stay on it it will hold it in gear until you get scared and let off.
All other gears seem to shift fine.

Tried removing the battery cables and "reteaching the throttle"

Even removed the box and returned to stock proram.
Still no change.

Any ideas? He will be taking it to the dealer this afternoon.

Thanks in advance.
Diesel Fool

 

Diesel Fool! GO to www.dieseltrans.com
You probably will get your answer. Hope this helps.