Shimming Coil Springs

[Tony_SS]

One side of my wagon sits a 1/4 lower in the front. The tire slightly rubs on this side over some heavy dips in the road.

I thought I read that you want to shim a front coil spring 1/8" to raise it 1/4". Can anyone confirm?

[aosborn]

Because the spring is inboard of the tire, a height change on the spring will be amplified at the wheel. How much depends on the distance between the inner control arm pivots and the spring centerline, and the distance between the spring centerline and the ball joints.

Andy

[Norm Peterson]

The ratio between shim thickness and ride height change is close enough to 2 in the G body for most practical purposes.

But I'd check the ride height between the frame and flat ground (left side vs right) in a few places to make sure that it's the spring(s) that need attention. Bad body bushings on one side could reduce tire clearance even if the springs were fine.

Are you by any chance running bigger tires or wheels than OE? Due to production tolerances, most cars aren't quite "symmetrical", and non-OE tire and wheel dimensions can sometimes uncover a problem on only one side.


Norm

[Tony_SS]

Thanks Norm, I'll check the frame height.

Yes I'm running 245/45-17 up front and 285/40-17 rear. Everything clears fine but the left side front and back sits 1/4" lower.