2001 GMC Sierra

[reid6384]

2001 Sierra Jerking around 45mph - 60mph

I have a 2001 Sierra that I recently had shackles put on the back to level it off. Now when I get to around 45mph the truck want to jerk and cut back. Once I get the speed up to around 60mph it stops. So I had the original shackles back on but still the same problem. Any ideas would be greatly appreciated.

Thanks,

 

[dano2001]

This does not make sense . Why would you want to raise the rear because the front end is the end that drops? and as far as your symptoms they are a little vague. And shackles?? just use blocks to raise is an inch or 2
Dano