Shudder when decellerating

[Cowboy_120]

I have found with my 3500 GMC 4x4 that when I am at highway speeds (approximately 120-130km/h, 75-80mph) that when I get off the gas pedal, the truck begins to shudder rather violently, making the passenger chair jiggle back and forth when empty. I have just put new tires on, but the truck did the same thing with the old ones as well. As soon as you begin accelerating again, the truck stops shuddering, and the ride is again smooth. Any ideas? Could it be tranny related? Thanks

[FirstDiesel]

Driveshaft????

[NutNbutGMC]

^.....Year model? Driveshaft (maybe)! TSB available for the fix.

[Cowboy_120]

Sorry, i forgot to include the year and model in my post. It is a 2001 GMC 3500 Crew cab 4x4 Long box. I had a previous problem with a seized u-joint, but that was fixed but it may be the drive shaft. It is going to the dealer on monday to be worked on, so I will let you know the outcome.

[NutNbutGMC]

^... 1-piece or 2-piece shaft?

In the case of a 2-piece, read here:

http://forum.62-65-dieselpage.com/ubb/ultimatebb.php?ubb=get_topic&f=7&t=003136

Good luck and happy dieseling.

[Joe Duffiney]

I believe the tsb was for the CC short bed and not the long bed. My truck was not included in the tsb. I don't have any problems at highway speeds but I do have the launch shudder at take off. I have gotten used to it now and if it was a serious problem I think it would have let loose while towing . Good luck and let us know what ya find out.