69 Radiator support to crossmember "special" shims

[Alan S.]

Re: How to adjust the radiator support crossmember?

Hi,
I just took a look at Patrick Hulst's 72 Bowtie car photos. (They're my life line!)
He has an interesting picture showing what appears to be 2 shims (1 each side) placed between the center bumper bracket and the front cross member at the bracket's rear bolts. They seem to have a clipped corner on the 'leg', but that's about all I can see.
Patrick, could you describe them a bit if you remember them, or take a new look when you get the opportunity?
Regards,
Alan

Nice picture Doug!

[Douglas P.]

Re: How to adjust the radiator support crossmember?

Greg,

Thanks, Doug, I think 1/16" is about right. Are they all the same thickness or could some be 1/8" as well? Do you know roughly how many were at each location?

All of my shims are the same thickness. I had 2 shims on the left side and 3 on the right.

Doug

[Roger G.]

Re: How to adjust the radiator support crossmember?

Greg,



Due to the condition of the shims removed from my vehicle, it is difficult to determine their original thickness. That said, I'd estimate that they were 1/16" thick.

Doug

I just came across this thread, during a front cross member swap. There were no shims present on mine, and a gap between the front cross member and core support. Maybe that's the rattle I've been hearing

About 6 months ago, I found three of them when I took the seats out...they were under the back of the seat tracks! Didn't know what they were at the time, but I saved them. They are exactly like the ones Douglas posted in the photo. Here's a pic of one of them on an OEM crossmember
E9872F28-0D9B-4C86-AF0E-7BC0D91FC1BC_zpspwql2xz8.jpg

Went down to a local sheet metal shop today to get some more fabricated. They are 16 gauge steel, about 1/16". They are going to fabricate 6 for me out of galvanized steel. Interestingly, the guy who runs the shop is a corvette guy, and a member of a local corvette club I belong to. Small world!

[Alan S.]

Re: How to adjust the radiator support crossmember?

Hi,
I've since seen the shims on a 69 Bowtie car and they look like what your picture shows Roger.
Regards,
Alan

[Roger G.]

Re: How to adjust the radiator support crossmember?

Thanks Alan, that's a great photo showing proper position. Here's another fun fact, they have a "GT" stamped on them
549A3E23-1B93-4426-AA4B-EE7719C315DE_zpsxhsfn2yv.jpg

[Alan S.]

Re: How to adjust the radiator support crossmember?

Hi Roger,
Does that make them qualify as a "speed part"?
Regards,
Alan

[Roger G.]

Re: How to adjust the radiator support crossmember?

Hi Roger,
Does that make them qualify as a "speed part"?
Regards,
Alan

Alan, only if they cure my mysterious rattle

[Douglas P.]

Re: How to adjust the radiator support crossmember?

I've since seen the shims on a 69 Bowtie car and they look like what your picture shows Roger.

Since it appears that these shims (GM P/N 3952926 "SHIM - SPECIAL") could be visible in the installed position, does anyone know if these shims were originally natural steel, or did they have some sort of plating?

Also, does anyone know if these shims were used throughout C3 production or were they limited to certain years (They appear in the '69 AIM 11-13 Sheet B4 Item #17, so we know they apply for '69)?

Thanks, Doug

[Terry M.]

Re: How to adjust the radiator support crossmember?

These shims show up in the 1970 AIM (Same page number, but item #14). However 1971 and 1972 AIMs are re-paged and sections UPC 11/13 are now separated and I can not find the Special shim or the drawing showing it.

[Alan S.]

Re: How to adjust the radiator support crossmember?

Hi,
The special shim, part number 3952926, is shown in the 1971 AIM in "Radiator Support & Brackets To Frame", UPC 11, on Sheet A10, and is Item 7.
There were none used on my mid-January built 71.
However there was this 'honey' used between the center of the front bumper and the large horseshoe shaped center bumper brace.
The 2 'extra pieces' are each welded to the larger piece in 2 places.
I don't see a shim of any kind mentioned in "Front Bumper & License Plate Bracket", UPC 14, Sheet A3, where I'd expect to see it.
Regards,
Alan

DSC_0846.jpgDSC_0850.jpgDSC_0847.jpgDSC_0848.jpg

[Terry M.]

Re: How to adjust the radiator support crossmember?

Hi,
The special shim, part number 3952926, is shown in the 1971 AIM in "Radiator Support & Brackets To Frame", UPC 11, on Sheet A10, and is Item 7.
There were none used on my mid-January built 71.
However there was this 'honey' used between the center of the front bumper and the large horseshoe shaped center bumper brace.
The 2 'extra pieces' are each welded to the larger piece in 2 places.
I don't see a shim of any kind mentioned in "Front Bumper & License Plate Bracket", UPC 14, Sheet A3, where I'd expect to see it.
Regards,
Alan

[ATTACH=CONFIG]53848[/ATTACH][ATTACH=CONFIG]53849[/ATTACH][ATTACH=CONFIG]53850[/ATTACH][ATTACH=CONFIG]53851[/ATTACH]

Good going Alan. The Special Shim # 3952926 is on the same page in the 1972 AIM -- same item number as well.

[Alan S.]

Re: How to adjust the radiator support crossmember?

Hi Terry,
Is that odd shim I posted the pictures of a typical production line part? It appears to have a very 'homemade' look to it.
If I wasn't the original owner I'd think it was something some body shop made to cure a 'gap' problem while doing a repair.
Regards,
Alan

[Terry M.]

Re: How to adjust the radiator support crossmember?

Hi Terry,
Is that odd shim I posted the pictures of a typical production line part? It appears to have a very 'homemade' look to it.
If I wasn't the original owner I'd think it was something some body shop made to cure a 'gap' problem while doing a repair.
Regards,
Alan

Alan,
I have no idea about that "odd" shim. It certainly does look home made, but I don't work in those areas and no one else has brought this to my attention.