MISSING BODY SHIM INFORMATION

[John H.]

The plant used a precision fixture which located at 3 points on the frame which were carefully controlled during build of the frame at A.O. Smith - Granite City, where all Corvette frames were made. The fixture "zeroed" at these three points and had spring-loaded plungers at each body mount location - the plunger position indicated how many shims were required in order to place the top of the body mount cushions in their design position. The body (floorpan) body bolt surface locations were pretty consistent, as the floorpan was a one-piece molded part, located on machined pads on the steel body build truck; the body was always assumed to be "zero", with all the variation assumed to be in the frame (if you had ever watched A.O. Smith fabricate frames at Granite City, you'd believe it). John

[Robert W.]

Re: Factory Shim Fixture Info

Thanks for the information. Are there any articles available that described the method in detail. Also which three points did the jig zero against? Thanks again.

[John H.]

Re: Factory Shim Fixture Info

Robert -

Can't remember much more detail than I posted (CRS, you know); can't remember which three holes were the "Master Gage Holes" that described a plane to measure the body mount heights from. I saw in another post earlier today that there's an article written by Noland Adams in the April issue of Corvette Fever that describes the process - I don't have the April issue yet, so I haven't seen it. John

[Gary G.]

Re: Factory Shim Fixture Info

Get the current issue of Corvette Fever as this very question is asked and answeared by Noland Adams.

[Robert W.]

Re: Factory Shim Fixture Info

Thanks- I wrote that question to Corvette Fever back in December and never heard a thing. Got my issue yesterday.

[Robert W.]

MISSING BODY SHIM INFORMATION

I am restoring a 1966 Roadster which was taken off the frame and body shim information not captured. From looking at the frame dimensions in the Chassis Service Manual can you level the frame and shoot the mounting brackets. From there I would assume you would make the highest mount zero and calculate the number of shims required to get the other mounts to their orginal reference position. I have been told put it on the frame and add shims but I postulate if sagging/drooping I have just continued the problem. Any ideas or help is appreciated. Understand at the factory they had a jig to set on the frame but it had to compare actual to theoretical some way.

[Brian Payer]

Re: MISSING BODY SHIM INFORMATION

Robert, I am currently restoring a '68 big block roadster. I had to repair the frame in the usual places due to it's former life sitting outside in the northeast. I leveled the frame using shims on the top of jackstands until the center 4 body mounts were equal, then used a bubble level to reference the other mounts. As you stated, I used the shop manual diagram, and with a little math figured out the relationships between the other mounts. Not very scientific, but now that the body is on, it has worked very well. Hope this helps. If you have any other questions, you can email me.


Brian #20841