Allison / Running Gear

[Dan Shaw]

I am having a sometimes reocurring problem when stopped at a lengthy traffic light. Starting off, the truck hesitates then a "bump" feel like something finally ingaging when starting to move. This does not happen all the time and especially not when the transmission mech. is riding with me. Any suggestions?

[ram/tx]

Do a search on this site about the bump. It sounds like you have the 2 piece driveshaft and some of the guys have had the bump with it. I think they have a TSB out to change this 2 piece to a one piece, but do a search and you should find your problem talked about here.

[Tractorhauler]

Dan,

I had the one piece drive shaft put in and that took care of the bump for me.
CC short box 02

[sspm1]

I have a two piece driveshaft and only notice it when the truck is not fully warmed up. Once warm the hesitation and bump goes away.