Anybody else get hopping when leaving a stop even in first gear. Have a six speed with a southbend clutch. Just put a set of caltracs traction bars on to stop axel wrap and I still get a bounce when getting the fifth wheel to move.

 

Sure it's not drive shaft whip? Common trait for a two piece drive shaft with a carrier bearing and a heavy load.

 

Nope replaced with a $700 one piece aluminum shaft years ago.

 

Any way you can post a video of what you're experiencing? Because I've never heard of this as you're describing.

 

Are the trailer brakes holding on too long? What kind of hitch and brake controller are you using also what is the truck?

 

U joints....

 

Sounds like the flywheel or pressure plate has some glazed up hot spots or the clutch disk does. Had that problem years ago on my 78 powerwagon after my mom would drive it for a day or 2. Nosed it up to a tree and slipped the clutch just till you could smell it.