could be a hanger bearing if you have one

 

I would go get my truck immediately, and tell them to cease all repairs on my vehicle. If you read that tsb all the way through and still don't know what I mean, do a search on this forum for "DEATH FLASH". A clunk when you put it in reverse will be infinitessamalously better than what they do to your truck with that drb.

 

Only the Hunter GSP 9700 balance center
can eliminate
tire/wheel/brake rotor
imbalance down to the point where you then
start looking for another vibration cause:

http://www.gsp9700.com/pub/features/how.cfm

If the first tire balance improved things
it is likely a better balance from a GSP9700
might eliminate the remainder of the vibration,
especially if the brake rotors are balanced and the tires
dismounted and matched to the low spots on the wheels.

 

Yep. It's your U-Joints. Cheap repair you can do on a Saturday afternoon. The replacement U-Joints will come with a Zerk fitting, so you can grease them at every oil change.

 

the u joints have NO play in them...
[align=left] [/align]

 

From the FSM:

VIBRATION

Tires that are out-of-round, or wheels that are unbalanced, will cause a low frequency vibration.

Brake drums that are unbalanced will cause a harsh, low frequency vibration.

Driveline vibration can also result from loose or damaged engine mounts.

Propeller shaft vibration increases as the vehicle speed is increased. A vibration that occurs within a specific speed range is not usually caused by a propeller shaft being unbalanced. Defective universal joints, or an incorrect propeller shaft angle, are usually the cause of such a vibration.



When you checked the u-joints for play ... did you make sure the driveshaft was unloaded (no tension on the driveline)?

 

how do you do that??

[align=left] [/align]

 

Get the rear tires off the ground.