Shim markings

[Jerry Clark]

trying to take the Top Flight target of the 1966 convert into consideration I have noticed something in Quanta's frame detail instructions previously unnoticed, (it is a new kit, maybe it is there in the old one....

1. "A "O" shim mark denotes no shims at that position"

Did the average line worker really take the time to write a "O" or did they assume that if there was no markings there were no shims?

2."The number two, (2) body mount displayed NO shim markings"

How did they know how many shims were required at this position and why were no markings placed here?

Thanks

jer

[Chuck R.]

Re: Shim markings

On my 68 frame at the #3 mount location, there was a circle in white lumber crayon on the frame side rail just below the mount.

For what it's worth.

Chuck

[Michael H.]

Re: Shim markings

Jerry,

The "0" marking for shim count on a frame rail was quite common. If one mount pad happened to be high, "0" would be the count so the worker at the next station on the assembly line knew there were to be no shims at that pad.

[Chuck S.]

Re: Shim markings

Hi Jerry,

It seems to me there have been threads on this board about frames using no marks for zero shims. You might try thrashing around the archives awhile and see what comes up. Within some policy definition (for example use of slashes or arabic numbers), some of the "style" of the markings may have depended on the individual actually doing the marking. Does your frame have mount positions with both "0" and "no marks"?

It seems like every frame should have at least one mount position with zero shims. There may be more than one position with zero shims, but it seems there should at least one zero shim position to set a reference plane. For what it's worth, my 70 frame has the zero shim position on the driver side at the frame kick-up (No. 3?). It was marked with a skinny zero with the left side open that some might question it WAS a zero. All the other mounts are marked with the arabic numbers, "1", "3", or "4", written more-or-less horizontal on the frame rail.

Sorry I can't give you better info for a 67.

[Michael H.]

Re: Shim markings

Chuck,

The "0" shim really never made sense to me either because I thought I remembered hearing that the fixture would measure the pad location and include a minimum of one shim. The measurement was taken at the small hole next to the larger body cushion hole so I suppose if the pad, or bracket, was welded on at a slight angle, it could result in a zero gap. I also wonder if the zero was dropped, possibly in the 70's, in favor of just leaving it blank when a quantity of zero was needed. I know I've seen the "0" on several 63-67 frames but I know almost nothing about 68 and newer.

Michael

[Charlie P.]

Re: Shim markings

I'm no expert on shim markings, but I think it would make sense to mark a zero for no shims-that way the installer would know that all mount locations had been checked. If there was no number at all, it might not be known whether that measurement had been taken or over-looked.

[Chuck S.]

Re: Shim markings

Michael, to make sure there is no misunderstanding, there were actually NO shims at the mount marked "0" on my frame. On the driver side, from mount No. 1 to mount No. 4, there were 4, 3, 0, 4 shims, and on the passenger side, 4, 1, 1, 1 shims. All shim counts matched the marks.

[Jerry Clark]

Thanks To All BUT

no one mentioned why no marking appear at the #2 mount, I found this to be the most curious part, it may remain a mystry
as always I appreciate the kind responses as does the owner Mr. Sanger
jer

[Chuck S.]

Re: Thanks To All BUT

As I said, Jer, positions with no marks happened...see the post below by Kelly Burnside on 22 Dec 2003. Unfortunately, no one in that thread knew why there were no marks on his frame either; At the one mount with a shim, the mark may have been lost to rust, but all the other mounts had NO SHIMS and NO MARKS.

This is probably an academic question as far as NCRS judging goes; I don't think the shim marks can be see anywhere except the no. 4 mount, but I am unfamiliar with C2s. You could either put the no. 2 mount back with a "0" mark, or leave it like you found it, which would be my course.

"My restorer pulled the body off of my 69 corvette Friday. Today I went down to look at the car. As an after thought, I decided to look for the shims from the car. When I got done, it was apparent that the car only had one shim under the #4 mount. All others did not have any. I looked at the aluminum spacers and all but one (which is the one with the shim) had tape over them from where they were taped to the frame with no shims. I also did not observe any shim marks on the frame. The one that had a shim I did not see any mark and I believe that that is because of surface rust probably erased the mark.
Now the question: How unusual is it to have a vette with only one body shim? (The perfect frame??)
Second and main question: When the manufacturer had no shims to add onto the frame, did they mark it with a "0" or did they leave it unmarked?
Another question I have is, if it goes back on the body and still does not require shims and I decide to not mark a "0", what will NCRS say if there are no shim marks on almost the whole car!! (I hate to have a car with a bunch of zeroes all over it!!)
Of course, when the restorer puts the body back on the car, he will reshim it as needed.
Any comments would be greatly appreciated as I think that I do have an unusual frame. One last thing, the body has never been off of the car and everything was aligned perfectly."