5ktq massive vibration from rear 20-40mph (solved)

[Kurt Deschler]

The vibration was due to the driveshaft balance weights rusting off and 
presumably further imbalance from flake rust. I found a good used 
replacement and the problem is gone. People in the rust belt need to be 
aware of this issue. The parking brake cables are easy to get to with the 
drive shaft out and can be easily changed at the same time.

 	-Kurt

On Mon, 2 Oct 2006, Kurt Deschler wrote:

>
>
> I am trying to isolate the source of massive vibration from the rear of my 
> 5ktq. The problem is definitely dependant of wheel speed, not engine speed 
> and comes on hard and fast at 20mph. Problem also occurs with the rear end up 
> on jacks. I tried adjusting the prop shaft bearing and geasing the U-Joint 
> and neither helped. I have also ruled out the brakes. Could the rear diff be 
> bad? It used to weep fluid so it is possible it went dry. The vibration 
> reasonates the entire back of the car and is enough to rattle your teeth out.
>
> 	-Kurt
>
>