The Door Mirror gasket thread

[Wallington]

OK so I'm constantly reading ads and guides on how to install Camaro and Firebird mirrors, then the various claims as to which GM gaskets work on which cars and which don't. Most are incorrect. This includes both original GM gaskets and the slightly modified repros that try to cover both models, only to read incorrect instructions on how to install, that a certain gasket suits both models or even that there is a LH and a RH gasket. So let's clear this up.

The different mirror gaskets come about due to the different door top angles between Camaro and Firebird models. There is a locating lug on the Left-hand end of the gasket for both models, the Camaro being located further out than the Firebird by about the width of the lug itself. The difference this creates is that one gasket will mount with the tapered thin-side up, the other with the tapered thick-side up. The locating pin hole on the right of the 2 screw holes is for the base model chrome mirror. It not only had to match the taper of sheet metal, but the mirror mount had a pointy end and a blunt end, so the gaskets needed to be directional as well. This created 4 gaskets over the 2 models and the hole spacing was different side to side. More on that mirror later.

If needing to check, the GM Firebird parts listing only mentions the Firebird gasket and that it requires 2. This guide does not include Camaro as F body.
The GM door mirror kits cater for both models and list the required gaskets for each model, just not why.

Firebird GM chart mirror gaskets mounting screw 67-76 manual by Ben, on Flickr

Firebird 9832127 mirror gasket listing both sides (2) by Ben, on Flickr

Firebird Camaro RH door sports mirror kits gaskets 9832126 9832127 GM NOS (2) crop by Ben, on Flickr

Here's a Chevrolet Parts listing for 1966-75 models, even though it was from a '77 revision. I've highlighted the 2 important sections that relate to the sports bullet mirrors. Note that the Camaro uses gasket 9832126....requires 2 of them...and RH or LH..... that's fairly clear for every online seller.

At the bottom is the 9832127 gasket that Firebirds use. I'm not sure why these smaller models had both types listed, but again, it's 2 gaskets, RH or LH. Not one of each.

Chevrolet Camaro mirror gaskets 9832126 LH RH chart 9832127 highlighted by Ben, on Flickr

The two GM original gaskets, 9832126 for Camaro and 9832127 for Firebird. The offset locating lug pin is seen on the left of both.

20230218_203956 by Ben, on Flickr

The Camaro gasket, with outer pin shown on left, Firebird on the right.

20230218_204131 by Ben, on Flickr

Same again, Firebird on left with thick side showing. Camaro with thin side.

20230218_204233 by Ben, on Flickr

Flipped over gets the opposite. Camaro on left with thick side up, Firebird with thin side.

20230218_204209 by Ben, on Flickr

This photo shows 3 versions of the door gaskets. 9832127 for Firebird, 9832126 for Camaro, and a Reproduction copied off the 9832126 with locating lug removed. Some have the GM number still in place, others are plain but are same combination of details. This Reproduction being the plain one by OER, yet the packet proudly claims it to be 9832126 still.

9832126 9832127 mirror gaskets Camaro Firebird OER for both by Ben, on Flickr


For the record, these are the sports mirror gaskets:

9832126 genuine GM gasket with locating lug pin - 70-81 Camaro only, both LH and RH doors.
9832126 reproduction gasket with pin removed and tapered base- 70-81 Camaro, both LH and RH doors and to lesser extent Firebird.
9832126 reproduction gasket with pin removed and non-tapered base (including 3D print) - Same as above but neither model will have level mounted mirrors possible.
9832127 genuine GM gasket with locating lug pin - 70-81 Firebird only, both LH and RH doors.

This is my 78 Firebird LH door. The black paint in a dark garage with poor lighting has been taped up to make more visible.

Let's start with the correct gasket for the Firebird. This is the 9832127, locating lug to the left, and thin side up. Remote cable hole lines up, if somewhat of a crude opening. Perfect.

Firebird door mirror gasket tests LH Repro 9832126 9832127 (5) by Ben, on Flickr


Now, using the correct 9832127 Firebird gasket but flipping it over. It is now thick side up like a Camaro, using the locating lug in the base-model mirror hole. Nothing lines up except the pin, plus the mirrors would be crooked.

Firebird door mirror gasket tests LH Repro 9832126 9832127 (6) by Ben, on Flickr


Now using a GM Camaro gasket 9832126. Locating lug on left used but Camaro offset and also thick side up, mirrors crooked, nothing lines up, cable hard to feed through limited opening.

Firebird door mirror gasket tests LH Repro 9832126 9832127 (3) by Ben, on Flickr


Camaro GM gasket 9832126 flipped over. Locating lug in the incorrect RH base model mirror hole. Nothing lines up, but mirrors would be straight.

Firebird door mirror gasket tests LH Repro 9832126 9832127 (4) by Ben, on Flickr


Now using the Reproduction by OER and others that used the Camaro 9832126 gasket as a sample then removed the locating pin. All well and good but often with no instructions, or incorrect ones. Thin-side up for Firebird so mirrors would be level, but awful alignment for remote cable hole. Can be used, but not great.

Firebird door mirror gasket tests LH Repro 9832126 9832127 (2) by Ben, on Flickr


And the Reproduction 9832126 Camaro gasket with pin removed, installed thick-side up like on a Camaro. Everything lines up again properly as no longer a pin, but Mirrors will mount crooked.

Firebird door mirror gasket tests LH Repro 9832126 9832127 (1) by Ben, on Flickr


Now, let's prove that there's no LH or RH gasket for the sports mirrors by copying test onto other door.

Here's the correct GM 9832127 gasket for the Firebird on the RH door. Locating lug to left, thin side up. Unseen, but the missing mirror cable hole also lines up. It is copied onto the inner mounting bracket that includes a cable hole for the RH remote mirror that Firebird never had. I meant to trace the opening of the hidden remote cable mount, just for alignment purposes but forgot, otherwise...Perfect.

Firebird door mirror gasket tests RH Repro 9832126 9832127 (5) by Ben, on Flickr


Firebird 9832127 gasket again but installed upside down. Locating lug in base model mirror hole, unseen remote cable hole is way off, but thick side-up as per Camaro means mirror is crooked.

Firebird door mirror gasket tests RH Repro 9832126 9832127 (6) by Ben, on Flickr


Things get interesting. This is the GM 9832126 Camaro gasket. Installed with locating lug in base model mirror hole on right, thin-side up for Firebird. Mirrors are straight and level, mounting is off centre of where it should be. So in theory this gasket combination will work, previous mirror mount location may be visible outside gasket on door paint, if you drilled new screw holes! Or cut off the locating lug. Plus, the gasket is now upside-down and they are not a true oval shape but have a flatter side and some mirror supports will really show this. So another fail.

Firebird door mirror gasket tests RH Repro 9832126 9832127 (2) by Ben, on Flickr


Now, GM 9832126 Camaro gasket mounted as per a Camaro, thick-side up, locating lug in left hole. Unseen cable hole way off, no screw holes line up, mirror crooked when installed.

Firebird door mirror gasket tests RH Repro 9832126 9832127 (1) by Ben, on Flickr


This is the 9832126 Reproduction. It has no locating lug to worry about just line up the screw holes. Remote cable hole is off but doesn't matter. Thin-side up for Firebird so mirrors mount level. This is another option where the gasket will work on Firebird but like the one 2 up, it is shifted sideways from the original location on door which may or may not matter.

Firebird door mirror gasket tests RH Repro 9832126 9832127 (4) by Ben, on Flickr


As above, the 9832126 Reproduction with no locating pin. Screws line up, remote hole doesn't and doesn't matter, but is thick side up for Camaro, crooked mirrors.

Firebird door mirror gasket tests RH Repro 9832126 9832127 (3) by Ben, on Flickr


Now, what's does any of that mean and why. How about we mount some mirrors. These were shown on the LH door with the correct and incorrect gaskets.

Correct GM 9832127 Firebird gasket, thin-side up. Mirror is straight and level, perfect.

Firebird LH door 9832127 gasket thin side up mirror straight (1) by Ben, on Flickr

Firebird LH door 9832127 gasket thin side up mirror straight (2) by Ben, on Flickr

Firebird LH door 9832127 gasket thin side up mirror straight (4) by Ben, on Flickr

Firebird LH door 9832127 gasket thin side up mirror straight (3) by Ben, on Flickr


Now, using the incorrect Reproduction 9832126 gasket with locating lug removed. The GM version with pin can't even be test fit without drilling and cutting...

No pin, thick-side up as per Camaro....horrible.

Firebird LH door 9832126 Camaro repro gasket no pin thick side up mirror crooked (1) by Ben, on Flickr

Firebird LH door 9832126 Camaro repro gasket no pin thick side up mirror crooked (2) by Ben, on Flickr

Firebird LH door 9832126 Camaro repro gasket no pin thick side up mirror crooked (4) by Ben, on Flickr

Firebird LH door 9832126 Camaro repro gasket no pin thick side up mirror crooked (3) by Ben, on Flickr

[FormTA]

I think I'm finally getting it! I have the original gaskets on my car. I'll have to see if I installed them right. I'm also curious to see what other gaskets I might have laying around. 

This is a great post! This will help a lot of folks! Thanks!

[5th T/A]

Ben, what a great write up. Unbelievable detail in your explanation and pictures.  My memory isn’t that great, so I saved it all in a folder on my iPad

Hard to believe on a somewhat simple part that was easily manufactured 50 years ago, yet the reproductions are so far off.

[scarebird]

The sad thing is unless I am reading this wrong, all vendors (including GM) of the gaskets could have made one version that worked on both cars and both sides - just would have had extra holes and an elongated cable hole.

[wheels78ta]

So after reading all about your research and comparisons..........I found an original set from a 75 Trans Am and from my Y88.  They all have 9832127.  All fit correctly on the Y88.  I also have a set of OER.  They are junk.  I'm guessing OER copied the Camaro gasket and not the Trans Am.
Thanks for all your research.

[Wallington]

Correct, copied the Camaro gasket, modified slightly, then listed as correct for both. Some places show how to install the gaskets but are only correct for Camaro.

Here's an example where they think they are helping but their details are only correct for one model. They have clearly never tested the other one before claiming they are the same and GM was wrong.

https://www.ebay.com/itm/354405985543?fits=Year%3A1978%7CModel%3AFirebird&hash=item52843e2d07:g:~j4AAOSwGWBkAbXc&amdata=enc%3AAQAHAAAA8LQF30pKnAyuqCPym4ZuaSGTYIub4QlXlhuMlHZIsTI3qOS15m5TzL5L1zKpYN82dE6gIeQGfj6P7DH3JbTN1uwP9HNw0VxS8N4oR7U1eNhnPxbifCvp22YxIUbjuC4AyfBgq4LY8DJnvU7fcTPPl1BWMDZkWPcu39GB0VoilofqXYGk7NKZmJT2SsG6tkhL2VGqRXPSxqfrsxzbWMJgqSi%2BqT1CeI3G8HlUnkD1HVC1o6TmN%2F5KCMGSOCLoFxdgAs137gB0764BexXSkA6BlDpJCVJqYFyA%2BTMiTvvLYlZRx8INavCGHjK6%2FgrZUe4GTA%3D%3D%7Ctkp%3ABk9SR77A7rreYQ

[wheels78ta]

It's sad that OER thinks they make an exact replica of an original GM product.  Same goes for the other aftermarket companies that think they have the correct dies to make and exact fit.  I call BS.
I have experienced OER products and all I can say is.........they suck for the most part.

[FormTA]

Ya, I see OER and I immediately think this part will be $&^!.

[scarebird]

I was able to flip each side 180° and now the mirrors don't look droopy eared.

Good work, Wallington

[Wallington]

Did you happen to notice what gaskets were on it? Looks better.

[Wallington]

Main post has had some pics replaced as didn't open in thread, hopefully sorted now.