Avanti Frame to Body Mounts

[RDadsAvantiII]

Hi! I have a 1980 Avanti that I Painted, and installed new Hog Troughs, about a year ago, I installed the Hog Troughs like the book say's, steel shims,I am noticing hair line cracks starting in the fiberglass,not bad but I would like slow down the stress cracks, I was wondering if anybody has a better sugestion, like putting rubber bushings inbetween the frame and the body,any information would be appreciated , Thanks Perry

[Thomas]

Perry, where exactly on the body are you noticing hairline cracks? Although you may have done it "by the book", are you sure that your Avanti didn't need more or fewer shims in some places?

Thomas

[RDadsAvantiII]

Perry, where exactly on the body are you noticing hairline cracks? Although you may have done it "by the book", are you sure that your Avanti didn't need more or fewer shims in some places?

Thomas

Hi! Thomas, my hairline cracks , I have 3 that I have noticed,one on the front fender driver side about 2 1/2" from the side of the hood, and a foot back from the front of the fender, I have cracks on both sides driver and passenger on top of fender on bottom side of back window, Thanks Perry

[Thomas]

I'm not sure how you measured for the shims, but most likely your body is not correctly shimmed. Cracks on the top of the front fender, usually towards the cowl, are common when the very front of the car has too few shims.

Thomas

[RDadsAvantiII]

I'm not sure how you measured for the shims, but most likely your body is not correctly shimmed. Cracks on the top of the front fender, usually towards the cowl, are common when the very front of the car has too few shims.

Thomas

Hi! Thomas, I am sure you are right, it wouldnt be the first time,I am thinking about trying to readjust body mounts do you have any suggestions, Thanks Perry

[Thomas]

Perry, unless you have a body jig to check dimensions it will mostly be a guess on how much additional shimming needs to be done. Basically you should loosen the front mounts, then jack the body up until you are uncomfortable jacking it any more - then add shims to fill the gap.

That said, I prefer to use hard rubber or polyurethane body bushings with shims as needed - rather than straight steel shims. I believe that it is important to allow for some movement, because your frame does slightly twist at times.

Thomas

[RDadsAvantiII]

Perry, unless you have a body jig to check dimensions it will mostly be a guess on how much additional shimming needs to be done. Basically you should loosen the front mounts, then jack the body up until you are uncomfortable jacking it any more - then add shims to fill the gap.

That said, I prefer to use hard rubber or polyurethane body bushings with shims as needed - rather than straight steel shims. I believe that it is important to allow for some movement, because your frame does slightly twist at times.

Thomas

Thanks, for the info, I will try that, I agree with you it seems like it would be too ridgit,Thanks Perry