1967 Carpet Dimmer Grommet

[Stephen L.]

I was gigged for the incorrect dimmer switch grommet at the Nationals. I've been unable to identify a correct grommet.

I visited a local junk yard and found these in various GM cars 1965-1968.

Are these correct for a 1967 Corvette??

They were made by NIAGARA PLASTICS ERIE PA. with 409 embossed on them.

The smaller diameter one is embossed with K-17 ALLIANCE PLASTICS CO. ERIE PA.

If not, how do I identify a correct grommet.

[Scott S.]

Re: 1967 Carpet Dimmer Grommet

Stephen, I was going to ask a similar question on dimmer switch grommets. I have read elsewhere that "Alliance Plastics, Erie PA" should be on the back, but that is definitely unconfirmed.

I can't find the one that came off the '67 at the moment. I do have one that was in a larger box I found that had NOS parts in it. Some were actual NOS parts (never installed) and some had original parts stored in the old blue & white GM boxes from when the original part was replaced with a then-current GM service replacement part.

The dimmer switch grommet was loose at the bottom of one of the large boxes, so I don't know what it is, maybe someone here does. Could be original (doubtful), service replacement, off of another car entirely, or old (1980s) reproduction for Corvette. The only marking is on the back, the letters "K F".

[William C.]

Re: 1967 Carpet Dimmer Grommet

Without checking, I believe originals were rubber, not plastic, Scott's pictures look good, again without checking any references.

[Rich P.]

Re: 1967 Carpet Dimmer Grommet

Originals ARE rubber and the Large grommets in Steves picture are correcgt. The smaller grommet has a different "ring" seperation from the original larger ones.

Rich

[Michael F.]

Re: 1967 Carpet Dimmer Grommet

years ago I took the original off old and installed on new carpet...problem solved for me.

[Michael M.]

Re: 1967 Carpet Dimmer Grommet

All the original dimmer bezels I have all have 409 and Niagara Plastics Erie PA embossed on the back side.

[Alan D.]

Re: 1967 Carpet Dimmer Grommet

Original on left from a 64 - no idea if it was same for 67.

How many point (s) were you hit for incorrect part? Assume the carpet weave, stitching, and a few other things were also NTP (not typical production) Find it hard to add up enough wrong things such as those mentioned to loose more than 1 point. Must also remember the judges are under a time constraint and rarely have time to figure point loss under the CDCIF requiremnts of Originality

[Stephen L.]

Re: 1967 Carpet Dimmer Grommet

Haven't received the official judging sheets from the Nationals yet, so I can't comment on official points deducted. The gig was verbal and noted on the sheet, possibly a point or two for the line item. No big deal.

I'm not faulting the judging, they did a good job. I'm just trying to clarify what a "correct" grommet looks like. The #409's that I got from some GM junkers sure look "plastic" to me, especially when they are labeled to have been manufactured by a "plastics" Co. The smaller dia grommet is also manufactured by a plastics Co.

How do the judges decide a correct grommet? I did notice that the edge of the smaller grommet is about 3/32" thick where a #409 is thinner around the switch hole. Maybe thats the clue???

[Jack H.]

Re: 1967 Carpet Dimmer Grommet

"How do the judges decide a correct grommet? I did notice that the edge of the smaller grommet is about 3/32" thick where a #409 is thinner around the switch hole. Maybe thats the clue???"

Judges will typically feel the surface texture of the grommet checking for hard vs. soft/pliable to determine rubber vs. injection molded plastic.

As far as mfgr identifying marks and relative geometry of circular rings go, the ID marks are on the back side and can't be seen during judging. Plus, I suspect there was MORE THAN ONE qualified supplier of the part which was pretty much true of GM's policy regarding not sole sourcing externally produced parts...

[Rich P.]

Re: 1967 Carpet Dimmer Grommet

"The #409's that I got from some GM junkers sure look "plastic" to me, especially when they are labeled to have been manufactured by a "plastics" Co. The smaller dia grommet is also manufactured by a plastics Co."

Stephen,

the originals should feel like an original alternator positive wire boot not like a black firewall tie strap.

Rich

[Joe R.]

Re: 1967 Carpet Dimmer Grommet

I was gigged for the incorrect dimmer switch grommet at the Nationals. I've been unable to identify a correct grommet.

I visited a local junk yard and found these in various GM cars 1965-1968.

Are these correct for a 1967 Corvette??

They were made by NIAGARA PLASTICS ERIE PA. with 409 embossed on them.

The smaller diameter one is embossed with K-17 ALLIANCE PLASTICS CO. ERIE PA.

If not, how do I identify a correct grommet.

Hi Steve:

After seeing your post a few weeks ago I acquired a couple of these grommets, and I remain uncertain about what is really correct for 1967. I'm hoping that some of our experienced restorers, who have taken apart a lot of original cars, can comment further on this topic.

It sounded like the consensus view from the previous discussion was that the "409 Niagara Plastics Erie PA" grommet is considered to be correct for 1967. However, this grommet appears to be plastic and is rather stiff.

I have another grommet that appears to be rubber but has no markings. While softer than the "409," I think it would be hard to tell the difference just by poking the exposed rim with a finger. The difference is most evident by comparing the large flat lip that is not visible in judging.

Comparison photos of the two grommets are attached. I have some questions I'd like to get some feedback on:

1) Have the "409" grommets been found on original 67 Corvettes?

2) Is it possible that the early C2 grommets were rubber and they migrated to plastic in later years? This would not be surprising given the evolution of materials and cost.

3) Is there any evidence that GM used two different suppliers for these grommets, and that both styles are "correct" for 1967?


I'm just wondering whether the "soft rubber grommet on all 67 Corvettes" is one of those NCRS judging myths that is not based on careful research.

BTW, did you record that year of manufacture of each of the junkyard GM cars that you pulled a "409" grommet from?

[Peter L.]

Re: 1967 Carpet Dimmer Grommet

The carpet dimmer switch grommet that is on my 67 has the KF embossed on the back and is definitely a softer rubber composition material rather than a stiffer plastic material. Is it the original? I don't know but it was on the car in '83 when I purchased it. Pete

[Mike M.]

Re: 1967 Carpet Dimmer Grommet

all of my current midyears, and all that have departed my presence, and all bowtie c-2's i've ever judged had rubber dimmer switch grommets.mike

[Joe R.]

Re: 1967 Carpet Dimmer Grommet

all of my current midyears, and all that have departed my presence, and all bowtie c-2's i've ever judged had rubber dimmer switch grommets.mike

Hi Mike:

Does this mean that none of the midyear grommets you have seen had the "409" markings?

I don't think we know 100% that the "409" parts are plastic instead of rubber, but the sample I have seems like plastic to me.


Joe Randolph

[Ronald L.]

Re: 1967 Carpet Dimmer Grommet

With modern chemistry there are 'plastics' that emulate rubber. Mid 60's was about that time we began with the plastics invasion. As a result plastics are made daily that are soft and pliable.

The only way to break the myth is to take a small snipping of the part that is hidden and do a simple test you can do at home. Rubber on the other hand - like tires - after 45 years... gets pretty darn hard.

I had understood this JG issue to separate 80's - 90's versions of 'almost'-reproductions to the originals, my original is pretty flexible but the its pretty hard rubber tooand its staying right where it is.

Sounds like we need a couple things:

A part number and one of the guys that has the GM part number cross reference to see where else in these mid years that number was used.

"Some" known originals - to know what is on the back of then. I expect across the entire GM line that there was more than one molding company. It could be the same part number, one used in Flint and Lansing, and others used at other plants in the mid west - for example.

For the brave soul that wants to break the rubber plastic myth, send an email & I'll describe what you need to do, the small clipping like a thumb nail size can be taken from the back side where its not seen.