OK guyd the vibration we experience from therear end is not what the dumb *** mechanics think. tires are great because the vibration is not at all times hell i have hit 102MPH in my truck vibration free it happened in the city a couple times and on the hiway 3 times in the last month. But I think that the guy in the head of the service department was right. it is not the tires it could be the clutches in the rear end screwin up so im gonna have it checked out friday.

 

Have them back off the emergency brakes a little. These for whatever reason rub at times causing the vibration. Did that a year ago on mine and no more vibration.

 

I seen the same thing happen on several. Park brake shoes rub and generate heat and start to grab causing a shake or surge. When the shake starts you can step on the park brake(hold the release handle and be careful), you will notice the shake gets worse or the pedal pulsates.