I've been experiencing a bad vibration at speeds over 70mph, and speeds over 60mph while turning. It's been going on for about a year now so I decided to try to figure out what it was buy replacing warn parts.

Over the past few weeks, I have replaced; CV Axles, half axles, half axle bearing and actuator gear, differential bearings, upper control arms, lower control arms, control arm bushings, struts, coil springs, upper and lower ball joints, inner and outer tie rod ends, sway bar links, stabilizer bar bushings, wheel hub assemblies, brakes, rotors, all u-joints, and carrier bearing. Got an alignment and re-balanced wheels. The truck still vibrates just as bad as it did before.

I don't feel it in the steering wheel, even though turning makes it much worse. Throttle position and brakes have no effect. I'm 100% positive it is not in 4x4. It feels like my seat is bouncing up and down. The whole truck rattles and the sound of my tools clanging around in the back is enough to make you deaf.

The drive shafts aren't bent or missing any weights. There isn't any play in the transfer case or differentials.

Any ideas?

 

Rear shocks? If you feel it in your seat. Usually means its in the back.

 

It only has one bounce when I jump on the bed and they aren't more than 6 years old, so I don't expect them to be bad. Why would a bad shock cause vibration at speed on the interstate?

 

Shocks only last 50-60k. The other purpose of shocks is to help keep the tires on the ground. Worn, broken will allow for excessive travel.

 

New shocks and helper springs did not solve the issue. I tried a few other things and had the dealership look at it. After dumping a total of about $2000 into this truck in attempt to solve this vibration, it is confirmed un-repairable. I took the insurance off. It's going to be a woods truck from now on.

 

Why is it unrepairable?