I've got a vibration on my 96 F-350 that I can't figure out. I've changed wheel bearings, rotated tires, check rotors, changed u-joints & carrier bearing. It happens between 25-33 and 65-70 MPH and varying RPMs doesn't change a thing. Any thoughts?

Thanks

 

Driveshaft may be out of balance. The rear drive shaft is balanced as an assembly and it tough to check yourself.

 

tire balance?? i would bet on it if it didn't vibrate at lower speeds too. but has it been checked? as cuda jim said driveshaft.

need more info on your truck, 4x? reg cab? tire size? etc....

 

Thanks for the help. I'll need to get the driveline balanced. I believe when I had the driveline out to change the carrier & u-joints I drove it to the parts store and still had the vibration. Either way, it eliminates one more possibility.

 

when you say you drove it with the driveline out i am guessing you drove it with the rear driveshaft out but in 4 wheel drive? if you still had the vibration with only the front working your looking at front drive shaft, front axle shaft, or tire balance issues. i wouldn't worry about the rear drive shaft at this point.

if this truck is 4 wheel drive. while in 2wd make sure the hubs are unlocked if they are manuals. and drive. if the vib still there. if it is then we are looking at tires more than likely, maybe some weird tran, t-case or diff problem but not likely.

if while driving in 2wd with hubs unlocked the vib is not there then you need to be looking at front drive shaft u-joint as well as front axle u-joints.

 

MAke sure your drive shaft "Phase" is like this.

 

i had the low speed vibrations that you have, i changed the u-joints in the rear drive shaft and the problem was gone. all the bearing were shot.