70 Rear Coupe Quarter Panel Trim

[Joseph M.]

Does anyone know the exact position of the odd shaped dark foam pieces that go under the rear quarter panel trim? They were taken off when the car was disassembled approx 2 years ago. I should have taken photos of this area prior to taking them out, but unfortunately didn't. Responses with pics or description would be great. Tx.

[Tom H.]

Re: 70 Rear Coupe Quarter Panel Trim

Hi !

I recently discovered these in my 71. They are called out here in My AIM. I can post a picture later if you like.

Part number 3922301-2 is listed in the AIM on UPC 1, sheet F31 as Rear Carpets & Insulators in the 71 manual.

[Don L.]

Re: 70 Rear Coupe Quarter Panel Trim

Tom, even if Joe doesn't need photos, I'd appreciate them if posible. I looked in my '72 AIM and found that these parts were eliminated in a Nov 26, 1971 engineering change. My AIM does not show the parts, their location or what seems was a detail view (VIEW A) of the area where they go. My '72 was built in August, so the expectation as to whether my car should have them or not is alive with this post. Thanks!

[Joseph M.]

Re: 70 Rear Coupe Quarter Panel Trim

Tom, tx for the info. We looked through my 70 AIM, but couldn't find any references. I'll look again under the section you specified. It sounds like Don would like a pic which I could also reference for my car. Tx.

[Tom H.]

Re: 70 Rear Coupe Quarter Panel Trim

I will get you guys a copy of the manual page. You should see them in the section where the rear carpet is called out.

[Chuck S.]

Re: 70 Rear Coupe Quarter Panel Trim

I will get you guys a copy of the manual page. You should see them in the section where the rear carpet is called out.

Unless we are confused by the description, we had a recent thread about these same spacers. The AIM page should be the perfect answer to the question. (Apparently, GM redrew the AIM sheets every year, if only to change the sheet number...In the 70 AIM, this is shown on Sheet F29)

The OP describes them as going "under the quarter panel trim"...actually the part numbers are stryofoam "spacers" that fill the rear void over body mount 4 bolts making the rear bulkhead flat all the way across. View A shows them standing vertically in that recess, small end of the taper on the bottom, with the "step-down" positioned inboard. Mine were white (July 70 car), not dark.

[Tom H.]

Re: 70 Rear Coupe Quarter Panel Trim

Yep. I started that other post. Mine were installed like yours. They were also white. Joe L. added to the conversation that they were never offered in service. Factory installation only.

[Don L.]

Re: 70 Rear Coupe Quarter Panel Trim

Yep. I started that other post. Mine were installed like yours. They were also white. Joe L. added to the conversation that they were never offered in service. Factory installation only.

Wow! This discussion board is a GREAT tool!

Tom, I had missed your earlier post on this subject. After reading your post that mentioned you had recently started a thread, I searched and found it. The pic of the part is there and very clear.

https://www.forums.ncrs.org/showthread.php?t=72726&uid=9913

Now I am very interested in this, as I have heard of these wedges before, but could never figure out where to actually look for them in the car. I looked through my AIM to find them with no success. Now I know why! They were evidently eliminated in an eng change during 1972 production. The date on the change is after my car's build date, so now I wonder if I should or should not have them in my car (could be the paperwork on the change was significantly after the actual change). Thoughts?

A couple more questions if you will, please:
1. These 2 threads are regarding C3 coupes. I have a convertible. Were these wedges in convertibles too?

2. I have access to this material in bulk. If I can get a dimensioned sketch, I may be able to come very close with repro parts.

[Warren F.]

Re: 70 Rear Coupe Quarter Panel Trim

I think this topic got misunderstood? I have two '71's, they have both the white styrofoam wedge pieces that are used in the rear bulkhead areas of both rear quarter panels.

These cars also use a dense dark grey/black foam rubber piece oddly shaped that can be partially seen by looking underneath the sides of the chassis.

I thought the original poster was referring to these pieces.

[Joseph M.]

Re: 70 Rear Coupe Quarter Panel Trim

I think there may be some confusion over the question I originally posted. I am familiar with both the chassis wedges and the styrofoam piecies in each corner of the rear bulkhead. The piecies I am referring to are black pliable foam, approx 1 inch thick, that go under the rear quarter panels above the seat belt retractors for the shoulder belts. I hope this clarifies my question and welcome responses.

[Joseph M.]

Re: 70 Rear Coupe Quarter Panel Trim

For further clarification, I am referring to the interior rear quarter trim panels. Tx.

[Chuck S.]

Re: 70 Rear Coupe Quarter Panel Trim

Wow! This discussion board is a GREAT tool!

Tom, I had missed your earlier post on this subject. After reading your post that mentioned you had recently started a thread, I searched and found it. The pic of the part is there and very clear.

https://www.forums.ncrs.org/showthread.php?t=72726&uid=9913

Now I am very interested in this, as I have heard of these wedges before, but could never figure out where to actually look for them in the car. I looked through my AIM to find them with no success. Now I know why! They were evidently eliminated in an eng change during 1972 production. The date on the change is after my car's build date, so now I wonder if I should or should not have them in my car (could be the paperwork on the change was significantly after the actual change). Thoughts?

A couple more questions if you will, please:
1. These 2 threads are regarding C3 coupes. I have a convertible. Were these wedges in convertibles too?

2. I have access to this material in bulk. If I can get a dimensioned sketch, I may be able to come very close with repro parts.

Don, one thing I've learned from John H and others is that the date of an engineering change shown on AIM sheets may precede the actual implementation of said change by weeks, even months. I doubt the change would have happened prior to the date shown on the AIM sheet.

Based on the fact that your car's build date (August 71) actually precedes the engineering change date indicates that your car SHOULD have the spacers IF convertibles had them.

I don't own, nor have I ever owned a 70-72 convertible, and have no intimate knowledge of C3 convertible rear compartments. However, the 70 AIM sheet (F29) showing this "View A" of the spacers indicates "Model" on the title block data as 19000. Typically, Model 19000 is used to indicate that the sheet applies to ALL Corvettes of this model year, coupe or convertible. If the sheet had applied ONLY to coupes, the sheet should have shown Model as 19437...for example, 70 AIM Sheet F19 for the removeable rear window locks shows Model 19437.

What actually happened on the assembly line is another matter altogether; your best bet is to have someone take a look at their original convertible for you ("Well, gee, Chuck, after all that, I'm right back where I started." )

[Chuck S.]

Re: 70 Rear Coupe Quarter Panel Trim

I think there may be some confusion over the question I originally posted. I am familiar with both the chassis wedges and the styrofoam piecies in each corner of the rear bulkhead. The piecies I am referring to are black pliable foam, approx 1 inch thick, that go under the rear quarter panels above the seat belt retractors for the shoulder belts. I hope this clarifies my question and welcome responses.

Joseph, I didn't find any foam rubber pieces behind my rear quarter trim panels, but there is no guarantee that I was the first to remove them.

I did find some black foam rubber "cubes" behind the lower rear window trim. In neither case are these foam rubber parts shown in the AIM leading me to believe that these rubber parts were applied to the trim by the supplier as a part of an assembly. I suspect the foam rubber is there to prevent resonance or the trim vibrating against the adjacent underlying structure (birdcage).

Unless you can get someone with an original car to pull a rear quarter trim panel for you, I suspect your options are to (1) study the structure underlying the trim panel to identify areas that may come in contact with the quarter trim panel during vibration, and/or (2) closely examine the back side of the quarter trim panel to determine if there is any adhesive remnant to give you a clue.

Since the part is hidden behind the trim panel, the primary concern should be to restore original function rather than precise placement.

PS: Here's another wierd idea...What if those "odd shaped" foam rubber parts you found were actually "packing" used by the supplier to keep the quarter trim panels from being damaged in shipment. Those quarter trim panels do not "nest" uniformly...those rubber spacers may have keep them stacked evenly. It's just an idea, but you can bet if a spacer clung to the backside of trim panel, they would only have taken the time to remove it if proper installation was thwarted.

[Joseph M.]

Re: 70 Rear Coupe Quarter Panel Trim

We found a pic of the foam piece in question. I didn't know a pic was taken, but the photo was shot by a friend who was helping me. It shows the piece in place, but it's function is a mystery. I'd post the pic, but it was taken with a throw away camera.