Center High Mount Stop Light/Third Brake Light Gasket Fitment?

[1SLwLS1]

I just bought this '04 Yukon about 6 weeks ago and this dang CHMSL gasket/housing is baffling me - how is it supposed to fit?? It doesn't look right to me and I can't find great pictures to see if this is normal (but weird and I just can't unsee it), or if this Dorman (923-044) gasket is just cheaply made and subsequently poorly fitting. If the latter, does anyone have a recommendation on brand/store on where I could source a properly fitting one? Or maybe the move is just to trim those ears back myself - just want confirmation on how it is supposed to be.

Backstory:
A few weeks back I was driving at some high speeds, testing the roadworthiness, as one does, and shortly after was hearing some intermittent thuds from what sounded like loose weatherstripping on the roof, even days later I would randomly hear the noise if it was really windy. I didn't notice anything loose on the roof and the factory weatherstripping on the rain water channels was only from the c-pillars back and it was secure. After hearing it intermittently for a few more days, I noticed the CHMSL gasket appeared very loose. I don't know if the floppy gasket was the culprit as I also deleted the roof rack the same day I replaced the CHMSL gasket but I haven't heard the noise since. The gasket that was on there before was visibly loose and in need of replacement but appeared roughly the same shape as the Dorman - hell it may've been a Dorman unit and already replaced before, this is a 22 year old vehicle and the grommet that secured the CHMSL wiring was unsecure from the hole in the rear. Other shade tree mechanics have been here, they did not cover their tracks very well.

So the first and second picture are how I think it goes, but it looks very weird, especially from grade. The third image I just folded those ears in, which doesn't stand out as much, but certainly can't be correct, you can even see the grimy edge of the old gasket where it trapped dirt so this position definitely cannot be correct. Thoughts?? Please help!

 

[Fless]

[BTW, yours is probably an '04, not an 04']

That's the later model liftgate glass, and I think someone may have swapped them out. However, I think the gasket is the same, but is that one up-side down? Here's my '04:

I'm sure others will comment.

 

[1SLwLS1]

[Fixed, thank you!]

At first, I was thinking maybe you're right (upside-down) as I just put it on the way the old one was but with the way you have to slide those two tabs for the mounting bracket through the gasket, I don't think it can go on upside down. I will have to double check.

What does yours look like from the outside with it closed? What year ranges did they differentiate the back glass? I know this thing has a new cheap rear bumper (chrome and plastic are definitely too new and poorly fitting to be OEM) and when I replaced the tail-light housings, some of the sheet metal bracing in the corner where the taillight harness goes through and connects underneath, that bracing was tweaked a bit and wouldn't allow the large plug to come through without me bending it back so maybe it was all replaced from one incident.

 

[Fless]

I was wrong about yours being the newer glass; you have the '04 glass that has a frame (rim) around it, just like mine. The newer glass started in 2005 IIRC, but it may have been mid-year. They're interchangeable from what I understand, and some people change them to have rimless glass. The rimless glass has a handle that is attached to the glass, and not part of the rim.

I'm not sure about the gasket, other than it looks like yours should be slid farther back on the light, at the top. The very top edge of the "ears" is the only thing that should be exposed; they continue inside along the body line and are mostly hidden by the window rim.

 

[1SLwLS1]

Got it fixed, I think. For whatever poor quality fitment reason, the new gasket was not allowing the light to seat fully into position, the center knub on the back of the light that rests in the alignment hole in the body was completely unseated and not in the hole. I wrestled with it for quite a while. I finally just cleaned up the old gasket, reseated the light in the old gasket, and it popped right into position. I don't know if the high speed driving previously pushed that whole assembly out and that is why it was floppy but we will see. Whatever shade tree worked on this before may've never installed it right because I know when I was looking for the flapping noise on the roof, the light was in the same unseated position so either the wind did pop it out OR it was never installed correctly and the roof rack was the noise. Time will tell. I also don't know if the old gasket was original but I know the light was a replacement, it is a Dorman unit so the new Dorman gasket should've fit right on, one would think, but oh well, I still have 3 days in my return window.

Thanks for the help.
-Mid

 

[LsHart]

Here is mine. 04 tahoe. Just installed it. When u hit the brake, it starts from the center and runs outward.

 

[1SLwLS1]

Sequential, that looks nice. Where did you get that one? I am probably done with lighting modifications for the time being, I've spent a little over $1K on new housings, HIDs, LEDs, etc.

 

[LsHart]

Bout to change it though. Looking for 05 caddy or tahoe with rear spoiler which will do away with this light. But nice for now.

 

[LsHart]

Sequential, that looks nice. Where did you get that one? I am probably done with lighting modifications for the time being, I've spent a little over $1K on new housings, HIDs, LEDs, etc.

From Carid.com. not to expensive. I went with red LED tail lights but this one is clear white. At least u can see me stopping.

 

[LsHart]

Sequential, that looks nice. Where did you get that one? I am probably done with lighting modifications for the time being, I've spent a little over $1K on new housings, HIDs, LEDs, etc.

Also have the front LED light set but bout to order a factory grille. So do it all at once. I can't find a black chrome grille. So factory repop will have to do.