overland

Thanks brokenarrow,
It is 4WD, and I have will try switching to 4H and see. I will also take a look at the front end.

brokenarrow

I saw another post that reminded me of something else to check. Take a look at your parking brakes. They can rust in the rotors causing the wheel to be 'off-balance'. You can see the attachment points from the parking brake cable on the back of the rotor assembly from under the truck. Another pretty simple check!

BadFish523

Overland I would recommend searching this forum for "vibration and shaking" there have been 3 or 4 people asking similar questions here lately. You may see a lot of the same info but you also might find some good checks such as the one brokenarrow suggested.

overland

Thank you Gentlemen,
I will check under the truck, and elsewhere on the forum.

BadFish523

Report back if you do or don't find anything. If you do it may help someone else to know what you found. If you don't find anything we will be here to help as much as we can.

overland

Thanks Brokenarrow,
The vibration does not go away when I shift into neutral or 4H. I just had the wheels re-balanced, they were only off by max of 1.5 oz. The tire shop did not think that road force balancing would change anything. While front wheels were off I looked/felt around front end - everything looked and felt tight. I checked other threads and found one that suggested the mount behind the transfer case at the connection of output shaft to drive shaft may be 'weak' and allowing movement - suggested replacement with heavyduty 'Raptor' mount. I also called a drive train outfit and they said they can check the balance of the driveshaft for about $100, but that would require laying up my only means of transportation for a day or so. Still looking to narrow down the possibilities.

TheOldRaker

I have this same problem, right around 55 mph. I have a thread about it already. I'm finally getting to trying to replace my u joints tomorrow, so I may have some more intel after that. Good luck.

overland

Thanks TheOldRaker,
Yesterday afternoon I found a large framing nail in my front left tire tread while feeling the tires for cupping. I took the vehicle back to the tire shop for repair. The manager offered to personally rebalance the tires for me. While on the dynamic balancer I suggested we look for 'radial runoff' and found several of the tires had considerable variance. I am riding in Firestone TransForce AT tires (LT165/70R17). The tire shop does not handle Firestone so the manager suggested I go to a Firestone dealer and see what they can do for me. So this may well be the source of the vibration. I will keep you all posted.

overland

No new tires yet, but I did just notice that the lower control arm ball joint bushings have cracked rubber! Looks like I will need to replace them. I hope to do the work myself, any suggestions?

overland

Control arm ball joint is tight - no play, so I will not replace until it becomes a problem. Increased tire pressure from 36 psi to 40 psi on a suggestion that the tires may "round out" with a higher tire pressure. Tires are rated to over 3000lb load at 80 psi. Feels like a slight improvement on the vibration.