1963 SWC Frame Shims

[Ray C.]

I started the shimming process on my 63 SWC restoration project today. I had to purchase a new frame, so the original shim count can no longer be used as a reference point. I set five shims at each mount as a starting point, but found that I would need way to many shims at the rear mounts and radiator mounts. I removed all the shims and set the body on the frame. The body is touching at #3 left mount (kick-up) and will require no shims. The balance of the mounts very from 3 to 6 shims except the rear mounts and they could require as many as 8 shims. What would have been the maximum amount of shims used off the assembly line?

Thanks for any help!
Ray

[mike mccagh]

Re: 1963 SWC Frame Shims

haven't ever pulled a midyear body with more than 6 shims BUT, use what what ever shim thickness it takes to get the doors fitting properly. if it takes way more than 8 shims at any one point to get alignment, i'd measure the thickness of the entire stack of shims at that body mount. say it come out to 1/4" thickness for 8 shims=.03" thickness per your current shims. then i'd make four .06 shims and insert the four .06" thick shims and bolt the body down. judges don't usually measure thickness of shims but shim count is as easy judging technique.good luck with your body drop. mike

[mike mccagh]

Re: 1963 SWC Frame Shims

PS: doubt the body is the shim thickness problem. its probably the repo frame but that's no big deal.mike

[Michael H.]

Re: 1963 SWC Frame Shims

Ray,

From your description of the shim count and the excessive amount required at the front and rear, (especially rear) I would have to guess that you have the frame supported with jack stands placed along the frame rails in a position that is allowing the frame to flex/bow, which will give you the exact problem that you describe. Typically, stands are placed at least 12-18" inboard of the front/rear wheel C/L and this means of support will cause this exact problem.

The ONLY way to accurately measure shim count is with the chassis supported at the front and rear suspension points. Instead of positioning the stands along the side frame rails, place the stands as close as possible to the C/L of the wheels. Supporting the chassis by the front and rear control arms would duplicate the shape that the frame will be in when the car is completed and sitting on it's wheels, and this was the exact method used at the assembly plant.

When you reposition the jack stands, you will find that the rear body mount pads will be at least 1/8" and possibly 1/4" tighter than your original measurement. If a body is bolted into position using your original measurements, it will be under quite a bit of stress when the car is completed and this will cause several cracks to appear in various locations on the body.

If you look in the archives, you will find a discussion on this exact topic with the exact same problem that you are having. When the poster repositioned the stands, he was surprised to find that the frame once again exactly fit the dimensions of his original shim packs. This is a very common problem and hopefully everyone will understand the problems they create when trying to align doors/panels or establish frame shim count with the chassis supported incorrectly. Hope this helps.

Michael

[Ray C.]

Re: 1963 SWC Frame Shims

Thanks Mike & Michael for the information.

Michael you are right with the assessment on where I am supporting the frame while shimming. I used this process with a 65 roadster and it came out perfect, but I had a shim count and replaced the original count and then just had minor adjustments for body lines and gaps. I am using a two post lift and have the lift points at the front of the rear kick-up and close to #1 body-frame mount. I will set it on stands today and check for variations.

I have numerous questions on this project, this is my first coupe. I will try to keep my quesstions down to one or two at a time.

I did use the archives to research the body drop, but must not have used the right key words. Tons of information, but could not find the posting that you were referring to. I will try again.

Thanks for all your help!!

Ray

[Michael H.]

Sept 12th & 19th post

Ray,

In the 2004 archives, search for the words "hanson, frame and flex". Select "all the words" and then look at the September 12th and 19th posts.

There's also some discussion about the differences in coupe/conv body flex which greatly affects the gap at the rear mount locations when the body is unbolted and the frame is supported as you mentioned. The conv body, lacking a roof, or upper member, will flex at it's center and follow the frame flex as the frame is supported on stands fore/aft of the wheel C/L's but the coupe body remains closer to design specs and a gap opens at therear mount location.

Michael

[Ray C.]

Re: Sept 12th & 19th post

Thanks to all especially Michael for the help in setting my 63 SWC body. The body is now bolted to the frame and the most shims used at any one mount was six. Michael you were right on the money. I used the lift and jack stands located under the the lower A-arms and the rear cross member. The space between the body and the mounts decreased dramatically at the radiator and the rear mounts.

Thanks again for all the help!!

Ray