May be normal, but I thought I would let the experts take a shot at it. When pressing my cruise button, the truck continues to accelerated 3-5 mph more than what I set, then settles back to where I set. My last truck which was an 03 HD Gasser did not do that. Also, today while driving on the Cherokee Turnpike, I held in the cruise button (coast) to reduce speed and when I let off the button, the truck jerked abruptly when engaging to the new speed. I don't seem to be having any other tranny problems. Didn't know if this was normal or not.

Mines an 02, and seem to have the same problem. For the
coast.....I let it drop about 5 to 7 down, without a thumping.
Think its the characteristic of the drive line. If you let it
drop less than about 5, it engages with the thump.





I'm certainly no expert, so hopefully more will chime in.

Mine drops 3 if it works. Sometimes I have no cc at all.

My 04 does it. I believe it is due to the larger dead band that GM added to the cruise control circuit on Dmax/Allisons. The larger swings in speed when the CC is engaged is to minimize shift busyness. When pulling a load the swings are more noticeable.