kenworth t800 vibration

Hey there.
If i was a guessing person, i would check the u-joints well. When unloaded the angle on the driveshafts might change enough to put the shafts in a position where a worn spot in the joints can cause this. Just a thought from someone who has been there, and done that. Good luck.

Dave p.

 

I had the exact same thing for the last few months.
From 45-55 I would get a bad vibration. If I held the truck at 50, it felt like there was a set of duals with a flat spot on them.

Tried several things at some significant cost.

4 new drive tires: not solved.
Balance all 8 drive tires: not solved.
2 new duplex steer tires: not solved.

After reading a couple of threads, I suspected a warn u-joint, as the vibration would go away when the truck was loaded. I didnt want to risk a failure and the subsequent collateral damage to the drivetrain, so I took it in for a look.

My dealer's shop found a worn yolk on the input shaft to the power divider. Replaced the yolk, shimmed the input shaft.

Runs smooooth as silk.

Hope this helps.