Vibration at 30-40 mph

[BillBaker]

NOTE: Not my truck, posting for a friend. Truck is a 2003 3500 dually, work truck, no mods.

Truck has had numerous front end work recently including new tires, end links, ball joints, and the driveshaft center support bearing.

The truck has a vibration at 30-40 mph. The last piece recently replaced was the center support bearing and this is when the vibration was noticed.
He took the truck back to the place and their diagnosis was that the front (only a few months old and $265/each) goodyear kevlar tires had flat spots.

Is this just a bluff as the truck is DD work truck? or lingo for separated belts in the tires?

So...they replaced the tires with some hankook tires (at no charge, saying goodyear did not warranty their tires) and the vibration is still there.

Could it be the driveshaft was not marked and set back in as it originally was and therefor out of balance? I live afar (10.5 hrs) from him so haven't seen this truck. What area/areas should be of concern?

I am not familiar at all with this truck AND on a side not he has NO mechanical skills so always just hands the truck over to the same mechanic.

 

[B.G. Smith]

Is the vibration frequency wheel rpm or drive line rpm? My guess is the center support bearing miss alignment. bg

 

[sag2]

The drive shaft should be marked before removal so it goes back in the same place. To replace the center support they have to split the two shafts so they now have three different places they could have got it out of phase or alignment.