One side sits higher than the other? 1978

[MYBAD79]

On the corner that sits low - check the diagonal opposite corner (i.e. pass front-driver rear) .... If you lift the driver side rear, the front pass side will come down....
Since you measured to the frame (front left/right) and those numbers agree with the front body (fenders) I'm thinking your problem is in the rear....

Example: if your driver side rear body mounts are shot it will raise the pass side front .... BUT.... The frame will stay "low"....

If your driver side rear susp is screwed up it will raise/lower the pass side front (incl the frame)....

1/2" is not much..... Could be as easy as a broken leaf on you (steel ??) rear spring....

 

[donnie1956]

Ordered a shortened 330 composite spring today from VBP. Hope to get it before the weekend and can then lower and tweek on ride height. The front is at the height I was looking for.

 

[MYBAD79]

Did you tell them you have the 550's up front? I'm surprised you're getting the 330 for the rear, the 420 would be a better match in my opinion.... At least the 360..... Maybe the shorter spring is actually at a higher rate than advertised?

 

[donnie1956]

Spring measured a higher rate around 345 with 1/2 inch shortened. Stance looks good and much closer to sitting level on all for corners. Next step is alignment.

 

[Belgian1979vette]

Solved it.

Just an update to this and FWIW. I managed to solve my rear unequal ride height issue.

Like has been said, the right front influences the left rear and the left front the right rear.

I measured every damn corner of the car and couldn't find any thing wrong with it. Then it dawned on me that the issue has gotten worse with the F41 stabiliser bar which is stiffer.

I thought that somehow (maybe weight distribution) made the front right sit lower on the spring. This would jack up the right rear. But because of the bar and the wheels that cannot be pushed further into the ground, the only think the bar could do was pull the lower right control arm upward, the spring would then push up the frame in the right front making the left rear go down....not sure if this makes a lot of sense.

Anyway, what I did was the following : I loosened up the stabiliser bar links and then jacked up the rear untill they were equal left to right. The made the front equal as well. I then reattached the left stabiliser link and torqued down the bolt. I tried to insert the bushings and the metal tube in the right but was unable to sense the distance between the stabiliser bar and the control arm was too short.

I shortened the tube about 15 mm and it went it. I torqued down the link and voila....rear stays equal left to right.:yahoo:

 

[MYBAD79]

If this theory is correct, then your car should sit level with the sway bay disconnected .... I'm suspecting that the unequal load on the sway bar is just compensating for some flex in the frame ....anyways, it's level now .... :drink:
Didn't re-read this whole thread but why not just a 1/4" (6mm) shim to the body mounts instead to make it sit level?

 

[rtj]

. I'm suspecting that the unequal load on the sway bar is just compensating for some flex in the frame

Yes, a bent frame or frame extension. My car is the same. Which is part of the reason for a future rebuild.

 

[Belgian1979vette]

sorry for the late response.

I have measured the frame several times during the body off rebuild. I could find nothing that was off. This was done based on the frame dimensions in the shop manual.

the front frame extensions are not at equal height that is correct. However, there is zero indication of it being hit.

BTW : I shimmed the body based on the dimensional differences of the frame versus everything being equal height and the differences in the cage (which was apart at the time). This way I now absolutly sure that the body sits correctly on the frame (did a bird cage swap, which made the original shim count useless)