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Here's the lowdown on mine. 2001 F350 CC LB 4x4 dually diesel, automatic. The truck has 22.5 inch alcoas on it. The speedo is off but guessing at around 45 mph the rear of the truck feels like it's hopping off the ground. Suspension/chassis is pretty much stock. My buddy put the wheels on when he had the truck and said he added a leaf in the front I believe (the truck sits level). Has bilstein shocks all around which really did not help anything. Have played with tire pressures some to no avail. Was under it today and the driveshaft seemed to have quite a bit of play in the carrier/hanger bearing. Don't haul much heavy stuff in the bed, but it rides much smoother when pulling a 3 car hauler gooseneck with cars on it (2 cars, at about 3300 lbs a piece). Actually rides better with just the trailer itself.

Sometimes doing about 75-80 on the interstate if you come off the gas real quick it will start a violent hop/shake. If you ease back into the throttle it will start to go away. It seems to change in severity depending on the grade of the road (going up or down a hill).

I need to measure the driveshaft angles once it stops raining, I've all but decided thats the culprit.

Any suggestions?

 

i'd bet that steady bearing is the culprit...

if its got enuf play when ur on and off teh gas it will def. cause vibration..

bet if u replace it teh problem goes away..

p.s. is the vibration new ? or always been there.. my gues is its a new problem..

 

Nope, always been there since he put the 22.5s on before I owned the truck as far as I know.