1967 Carpet Dimmer Grommet

[Mike M.]

Re: 1967 Carpet Dimmer Grommet

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

i never noticed the presence of markings on the undersides of the grommets, but then again i was unaware and not looking for "409" etc. sorry,mike

[William L.]

Re: 1967 Carpet Dimmer Grommet

Stephen
For what it's worth. Here's pictures of mine out of my 67 and I'm about 98% sure that it is original to my car. It also has the 409 and Niagara Plastics on it.
Bill

[Joe R.]

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.

Hi Ron:

Thanks for the info. We probably don't need to resort to actually testing the material, but it is important for people to understand that saying the material is "plastic" or "rubber," based solely on poking it with a finger, is risky.

From the responses so far, it appears we have two versions of the grommet that have been found in believed-original 1967 Corvettes:

1) One marked "KF" that seems to be rubber
2) One marked "409" that is a bit stiffer and may be plastic

With further research, it may turn out that both versions were in fact used by the factory. If so, and the "409" version is not passing the judges' finger-poke test, we need to update our approach to judging this part.

[Scott S.]

Re: 1967 Carpet Dimmer Grommet

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.

[Scott S.]

Re: 1967 Carpet Dimmer Grommet

I have not been able to find GM part number 4591473 in my earliest Corvette parts catalog.

[Alan D.]

[Scott S.]

Re: 1967 Carpet Dimmer Grommet

Hi Alan,

If GM # 4591473 had been discontinued or superseded before April 1, 1970 then it should be listed in the January 1965 - April 1970 Parts History catalog. If it was not discontinued or superseded before April 1, 1970 then it should be listed in the 1970 P&A (effective April 1970).

I did not see GM #4591473 listed in the 1970 P&A or the Parts History catalog for 1965-1970... yet it is listed in the 1964 and 1967 AIM (and presumably in the 1965 & 1966 AIMs, maybe 1963 too).

[John M.]

Re: 1967 Carpet Dimmer Grommet

Joe,
I have an original grommet and will check it when I get home next week.
99% sure it's the original 67 item.
John

[Scott S.]

Re: 1967 Carpet Dimmer Grommet

This is everything I can find for the Dimmer switch in the 1970 P&A 30B catalog, the 1965-1970 Parts History Catalog and the 1967 AIM. The dimmer switch parts appear to be part of group 2.459, but I do not have any illustrated examples of that group:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

CLIP. Headlamp Dimmer ......................................... 2.459
PEDAL, Headlamp Dimmer ....................................... 2.459
PLATE. Headlamp Dimmer ....................................... 2.459
SWITCH. Headlamp Dimmer .................................... 2.459



2.459 SWITCH - PLATE - CLIP - PEDAL, Headlamp Dimmer

53-55 ..... Corvette (6 volt) .......... 1997008 .......... 2.71 .......... 3 overall length ........................... 1
55-62 ..... Corvette ..................... 1997023 .......... 2.71 .......... 2 hole mounting flange (Note 1) ..... 1
............... NOTE 1. 1955-56 model initial installation also requires connector 2962449.
68-70 ..... Corvette ..................... 1997028 .......... 2.15 .................................................. ......... 1
63-70 ..... Corvette ..................... 3915692 .......... .25 .......... PLATE, switch mounting .................. 1
68-70 ..... Corvette ..................... 3922387 .......... .30 .......... PLATE, dimmer pedal mounting ......... 1
67 .......... Corvette ..................... 1361699 .......... .10 .......... CLIP, stop lamp switch ................... 1
68 .......... Corvette ..................... 3922386 .......... .80 .......... PEDAL, dimmer switch .................... 1
69-70 ..... Corvette ..................... 3940687 .......... .75 .......... PEDAL, dimmer switch .................... 1


69 Corvette ............................... 3958861 .......... 2.65 .......... PAD, floor carpet dimmer switch (comb: 427, 428) ... (green) .......... 1

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


Only two items above are mentioned as being for 1967:

67 .......... Corvette ..................... 1361699 .......... .10 CLIP, stop lamp switch .............................. 1
63-70 ..... Corvette ..................... 3915692 .......... .25 .......... PLATE, switch mounting .................. 1

The actual Dimmer Switch (GM # 1997028 in the 1967 AIM, UPC 12, Sheet B6) is not listed in the 1970 P&A as being applicable for 1967, but that part number (1997028) is listed as being applicable for 1968-1970 (see above).







~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
68-70 ..... Corvette .......... 3922395 .......... .10 .......... GROMMET, actuating light switch push rod
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

GM # 3822395 is not listed in the 1967 AIM, and not listed in the 1965-1970 Parts History catalog.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
15.300 GROMMET --- RETAINER, Front Floor
63-67 ..... Corvette .......... 3826385 .......... .05 .......... RETAINER, carpet support .......... 1
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[Scott S.]

Re: 1967 Carpet Dimmer Grommet

I forgot to add:

Joe Lucia--

Where am I going wrong?

[Jack H.]

Re: 1967 Carpet Dimmer Grommet

I'm beginning to think we're fighting/perpetuating an urban legend here with various JG books saying this part (dimmer switch grommet) should be rubber & judges asserting anything else is a 'reproduction' part. Why?

Well, the grommet is GM PN 4591473. It's called out in the AIM books from 1956-67 for Corvette. P&A Catalogs that service both Corvette and Chevy car/truck, also call out that PN for both Corvette and passenger car for the '53-67 era. It's listed in Section 15.300.

If I remember correctly some cars and trucks had carpeting as an OPTION, so you can't depend on the grommet being a part of the base vehicle in every year! Also, my copy of the '64 P&A Catalog (contains 1938-64 Chevy passenger car, 1953-64 Corvette and 1938-64 Truck) calls the part as being applicable to "ALL + CORVETTE" then goes on to make a descriptive statement "with 1-inch ID".

I've pulled grommets from scrap yard cars of many different years and observed grommets from Niagra, Steele, Unmarked and Applied. All of the grommets I've found from Steele were soft and rubber like while the Applied and Niagra were firmer/stiffer to the touch, like plastic vs. rubber.

I've pulled Niagra grommets from both a 1960 Chevy and a 1966 Chevy Impala. These cars were quite pristine in terms of their carpet and carpet underlyment. The '66 Impala was built in St. Louis. This tells me the 'plastic' version of the 4591473 WAS an inventory item at the Corvette plant...

I'm beginning to draw the conclusion that:

(A) This was a purchased part.
(B) There were several qualified vendors.
(C) There were vendor to vendor differences in the basic part.
(D) To believe, publish and judge that ONLY ONE version of the part is correct/original to Corvette is a LEAP of faith!

[Joe R.]

Re: 1967 Carpet Dimmer Grommet

Hi Jack:

I agree with your assessment. I participated in this thread when it first started, raised the same questions, and never saw any final consensus. I suspect that the Niagra Plastics 409 grommet (which appears to be clearly made of plastic) may well have been used in Corvettes.

In the mean time, I found an inexpensive soft rubber reproduction that, as I recall, is for a 57 Chevy or something. Anyway, it looks great and is quite soft, so I will install it if/when I get my car judged again. I suspect, though, that the "soft rubber" requirement that some judges impose is just one of those Corvette judging urban legends.

[Jack H.]

Re: 1967 Carpet Dimmer Grommet

'Soft' to the touch and 'rubber' may be two different things. I won't swear you can't obtain an injection moldable plastic that's virtually impossible to distinguish from rubber...

The Niagra and Allied carpet grommets I pulled from scrap yard Chevys were all harder material that I suspect WAS plastic and, as I said, I pulled at least one of these from a 1960 Chevy AND another from a 1966 Chevy Impala built at the St. Louis plant. As the thread already mentioned, the trend to plastic probably increased as time progressed (cost savings) and the same GM PN for the grommet dates back to and before 1953...

So, gotta have a 'rubber' grommet to make those interior judges happy (we should have to do this IF there really were plastic grommets used on Corvette), go out and find a very OLD Chevy passenger car. Also, be aware that there was another, smaller, grommet used and the key is a 1" ID hole for the dimmer switch to stick through.

A reasonable amount of the judging information we learn is passed down by word of mouth from older, more experienced judges. But, that doesn't make the information right! I often hear 'proof' to the effect "I've never seen an original Corvette with this/that" and that's NOT telling me that the drawing was pulled, examined, and researched to support the conclusion.

Yes, some 'original' Corvettes come to us for judging, but our due diligence factor is 'typical factory production'. You'd have to see a LARGE number (thousands) of untouched factory original Corvettes to conclude you know exactly where the limits of typicial factory production variance lies!!!