BarryB72

I got around to measuring my trim height, I guess it's called. My passenger side is around 1/4 inch higher at the top of the wheel openings and I do have body shims I can remove.

If it's a viable solution, what do I have to loosen to be able to get the weight off each mount just enough to slide the passenger side shims out?


Will removing shims affect the front wheel opening height at all? No point of lowering just the rear and the right front is the biggest offender. With the tires I have I should be at 27 1/2.

Driver front is 27 3/4 but right now front passenger is 28 1/16

Right rear is 28 1/16 to 3/16 depending on the day and that's as low as it will go, but there's a 1/4 inch of shims back there. Guess my guy needed a place to put 'em. Looks like there's 2 shims up front. Not sure how many in between.

I've been driving the car for about 3 years now, if that matters.

bazza77

Shims are there to keep the body straight and uniform by compensating for the variation in the c3 frames . The reason 4 were in one spot is your frame is lower there than optimum or maybe say average . Its not a bad thing , there are cars with more shims in one spot .

If your door gaps ,hood gaps and alignment , bumper alignment are all good why would you mess with them by changing shim height ?

I haven't even mentioned rust and body mounts or suspension work.

terrys6t8roadster

Look at where the very front of the body mounts to the frame, around the lower core support area. If it's a solid mounting to frame there changing the shims at the #1 and #2 body mounts won't change the 28 1/16 measurements. Our chrome bumpers bolt to brackets that are bolted tight to the frame. T

Alan 71

Hi Barry,
Originally the frame was 'measured' in a 'jig' at St.louis to compare it to the engineering specifications and dimensions. This was done while the frame was being assembled and was before the body was put on the frame the first time. The shims have to do with the frame… not the body.
The number of shims at each location wasn't changed once the body was placed on the frame….there was no way to do it.

Ride-height has nothing to do with the body shims; ride-height is determined by the suspension. So that's where you should be looking to making an adjustment……. if needed.

There are VERY few ways to affect the FRONT ride height beyond choosing parts with specifications similar to the originals and ensuring that they are assembled correctly.
The REAR ride-height is a function mainly of the rear spring's specifications and installation. The condition of the rubber bushings on the spring to trailing arm bolts can also have an effect.

Unless the body to frame shims and pucks/bushings are in EXTREMELY deteriorated condition they're not causing what you're seeing.
Regards,
Alan

The frame being 'measured'… note the frame hasn't been turned over yet (they were assembled up-side down), and, the tool used to determine how many shims were required at each body mount location.

69Vett

you do Not adjust ride height, by removing body shims.

BarryB72

Thanks guys. I'm just LOOKING for something to work on. Just got new door windows in and I'm afraid I'm running out of things to do that only requires screwdrivers and wrenches.

dariopop

You can adjust rear side to side height with the rear spring bolts. Adjusting rear spring bolt will have an effect on the front also. Are both rear heights the same, you only mentioned one rear height.

BarryB72

I had already lowered the passenger side rear by about 7/16 inch by taking the nut all the way to bottom of the bolt.

With my tires the rear should be 27.75. My right rear is 28 1/16 now. Driver rear was around 27 15/16 and I think I could have lowered it if needed but I tried to raise it using the spring bolt. That actually had little affect raising it. Maybe 1/16. So it's right at 28.

Front heights are the issue now. Fronts should be 27.5 with the tires I have up there but front left is 27 3/4 and front right is 28 1/16.

dariopop

Lowering the rear spring bolt nut actually raises the height. Screwing the nut up lowers it.

Alan 71

Hi,
I believe that typically:
tightening the nut on the spring to t-arm bolt (shortening it's effective length) RAISES the ride height.
loosening the nut on the spring to t-arm bolt (increasing it's effective length) LOWERS the ride height.
Regards,
Alan

69Vett

"Lowering the rear spring bolt nut actually raises the height. Screwing the nut up lowers it."

wrong... you buy longer bolts to lower the ride height.
or in this case run the nut to the end of the bolt/cotter pin for max. lower ride.

chevymans 77

Loosen the core support bolts and use the two large bolts on the bottom of the vacuum can to adjust the height of the front of the car. The holes in these brackets are large to allow adjustment. You may also have to loosen the front crash bar brackets if you need to move it a good distance.

Support the front of the car prior to loosening these bolts,

The 72 should be close to the 77 in design,

Mine was like yours and this is how I adjusted it,

Neal

M Pete

Any chance you could take a few pics of circle the ones you are talking about on a diagram?

My passenger side is pretty high. Looking under the car at the sway bar you can really tell as the body has a much larger gap between it and the sway bar on the passenger side.