Body shimming on mid year coupe

[Norris W.]

(I REFUSE to refer to Corvettes as C-anythings until they're 90's & newer)

Anyhow, two of my 63's have been in boxes for years and were bought that way (1 coupe, 1 conv. off chassis, 1 coupe never removed) I'm strugglin' to get the scattered coupe together now and don't know where to start on the shimming, since the marks were long gone on the chassis. Seems like the conv. will be easier because door fit will be easy to spot, but seems to be less likely to use as a guide on a coupe.

All this ole' junk IS GONNA' roll before I die.

[Jack H.]

There's two approaches to shimming...

The first is 'seat of the pants' and don't laugh, the good ole boys with experience do a pretty darn good job here! They lay the body on the chassis, walk around, eyeball the body's stance + seam lines around the doors and lay in shims as required to make the body sit 'right'...

The second approach is maybe technical 'overkill' but it parallels the factory original method. That merits explanation...

At the factory they had a special frame jig and lowered the frame onto a known flat plane and STOPPED when first body mount made contact being the highest of the mounts. Sometimes by random chance, there'd be more than one 'high' mounts that were exactly the same height (zero shims).

Then, rather unskilled workers would test fit the other, lower mounts, with shims and mark the frame adjacent to each mount with the number of shims needed to bring those lower mounts up to approximately the same height as the highest mount. That provided a flat/level platform for the body to lay onto the frame.

So, the same thing can be done by getting the frame level on the ground and sighting from each body mount to the others to determine the highest mount. With this as a reference, look back to the other mounts (laser beams are pretty cheap these days) and figure out how many shims it takes to bring each mount up to the level of the highest...

[Vincent F.]

Re: There's two approaches to shimming...

Also you may want to have your frame sitting on with wheels and tires for shimming.I found that when my frame was on jack stands it flexes to much to be accurate,had problems at doors on convertible

[Joe C.]

Re: Body shimming on mid year coupe

Hi Norris,

Are your C2's equipped with L75, L76, L84, or standard?

Joe

[Norris W.]

Re: Body shimming on mid year coupe

Daggumit Joe, you made me get my NCRS Spec Guide out to remember what all those L's are. The convertible is L84, local car disassembled in '64 so hot rodder's mom couldn't sell, with 4066 miles and never re assembled in all these years. I jeered at a couple of previous owners who had the po' thing and didn't make much progress, and I've had it for over 20 years myself now, and it's still not back together........... but I'm gainin' on it) 1 of the coupes is original engined L76, disassembled in '75 or '76 by previous owner, which I've also owned for over 20 years and can't get it assembled either, but I'm gainin' on it too. 3rd is L75 with original motor gone, but still lookin'. Bought it rolling but stripped sometime in 80's........... not gainin' on it at all.

Side note: Somebody off the board here sent me an E mail a while back and asked me why I usually refer to my convertibles as convertibles, rather than roadsters. The late Dale Pearman made an impassioned speech at Bloomington (I think it was) about why drop tops Corvettes were convertibles and NOT roadsters, and that any real Corvette guy would know the difference. I always called em roadsters myself, but in memory of Dale, I've tried to clean up my lingo and refer to em as he wished, although I DO HAVE occasional relapses. Still ain't no-body gonna get me callin' early cars C's. I always hafta' take off my shoes and socks and use my toes to count on to try and figure what year somebody's talkin' about when they're usin' all them C's with numbers after em, and it just ain't worth it.... hell, it makes my brain hurt just tryin' to figure it out. Far as I'm concerned there ain't nothin' but straight axles, mid years, and late models.

[Norris W.]

Re: There's two approaches to shimming...

Actually I'd been thinking about trying to shoot the chassis with a laser, but figured there was some trick before I got into all that. I figured the chassis was the variable, since something was measured and shim marks put on it, obviously before the body drop. What I couldn't figure for sure was, if the chassis WAS the variable, did that mean that the body mounts were THEORETICALLY on parallel planes.

[Wayne W.]

Re: There's two approaches to shimming...

It always interested me that the body made of fiberglass was built to exacting standards and the frame made of steel was a haphazard mess. Just dont seem right does it? But, the problem now is that that body has probably been though hell for forty years, and there aint no guarantee that it is anywhere near what it is supposed to be. So, I dont think the lazer level thing holds much promise. Just place the thing on the frame and work it out. Its not hard to do.

[Joe C.]

Re: Body shimming on mid year coupe

Glad you took the time to have some fun with me, while getting the "dope" on the best way to shim your Corvette.
All's I can say about that, is, since you want to minimize shims, and you have no reference point, then trial and error is the only way. I'd start with none, all around, and add shims as needed to get your door gaps right. I'd then roll and jounce the car on a dead level surface, and add shims at all 4 (5) locations if one side is low. I think that Zora, being the perfectionist, would prefer the car to be level across the beam with an average sized driver in the seat. There are probably shortcuts that the experts use, but that's the basic idea.

Joe

PS: I don't like using the "C" word either. If it does slip out, on occasion, I often think about how inappropriate it sounds.
I usually call the generations: Straight Axles, Midyears, Sharks, C4's, C5's (or Fat Asses), C6's (or Fat Asses with exposed headlights).

I have never seen a Corvette ragtop with a rumble seat, so I call them convertibles.