2012 cc 6.2l vibration

[dgrinnell]

Ok guys I'm have a vibration when I get up to 62mph and over. It vibrates so bad that the pass seat is moving. I don't really feel it in the wheel. I had a similar vibration when I bought the truck new but not as bad that one just went away. Now its back and worse. Any ideas... maybe balance?

[Wolfmanjohn]

I'd be looking at rear tire balance. If I were driving unloaded, which I usually am, I'd also reduce rear tire pressure to the same as the front.

[oldmann]

Mud or rock in wheel. Or maybe a broken belt in a tire.

[pm26]

Ok guys I'm have a vibration when I get up to 62mph and over. It vibrates so bad that the pass seat is moving. I don't really feel it in the wheel. I had a similar vibration when I bought the truck new but not as bad that one just went away. Now its back and worse. Any ideas... maybe balance?

That's a little vague. Certain amount of small vibration in an empty passenger seat is normal even with perfectly balanced tires. Do you feel any vibration in the floorboards? Is the passenger seat shaking really bad? As mentioned, the cause are usually the rear tires. You could have a tire out of balance, but you could also have an out of round tire, or a tire with a broken steel belt.

[dgrinnell]

The vibration is bad enough where the seat makes noise. I was looking at the rear wheels last night and noticed one wheel had no wieghts on it at all. So my guess is that ther are our of balance.

[pm26]

The vibration is bad enough where the seat makes noise. I was looking at the rear wheels last night and noticed one wheel had no wieghts on it at all. So my guess is that ther are our of balance.

Jack up the rear of the truck by the differential until the rear wheels are about 1/16" off the ground. then put the truck in neutral and spin each tire by hand, observing any up and down motion of each tire. I usually take a piece of 2X4 and place close to each tire while spinning it to see if the tire is out of round. Out of round tires are defective and will cause unpleasant thumping that translates into vibration at higher speeds and cannot be corrected by balancing.

 

Sometimes a tire may be so good that it does not require any weights to balance. I have had a few of these, but they are rare, especially on a pickup truck.

[dgrinnell]

Well it ended up being just a tire balance but I have a long story that I just posted about my ordeal with the tire shop today...