Author Topic: Taillamp Gaskets  (Read 7226 times)

Offline ehjorten

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Taillamp Gaskets
« on: November 20, 2017, 12:54:21 PM »
So I recently replaced the taillamps on my '77 K20.  I got the taillamps as an assembly with the housing, lens and gasket that goes between the housing and lens, but did not get the gasket that goes on the back of the housing that goes between the bed-sides and the housing!

I can't seem to find these!  Does any parts house offer these?
« Last Edit: November 20, 2017, 04:41:18 PM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline VileZambonie

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Re: Taillamp Gaskets
« Reply #1 on: November 20, 2017, 02:25:55 PM »
That's because there isn't one
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline ehjorten

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Re: Taillamp Gaskets
« Reply #2 on: November 20, 2017, 04:40:28 PM »
I beg to differ Vile!  My stock 1977 K20 lamp housings had gaskets adhered to the back of the lamp housings!
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline blazer74

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Re: Taillamp Gaskets
« Reply #3 on: November 20, 2017, 05:03:15 PM »

Offline ehjorten

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Re: Taillamp Gaskets
« Reply #4 on: November 21, 2017, 08:44:47 AM »
Blazer;

Any part numbers for reference on that gasket?

EDIT...think I found the parts catalog page:


Thanks,
« Last Edit: November 21, 2017, 09:02:05 AM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline blazer74

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Re: Taillamp Gaskets
« Reply #5 on: November 21, 2017, 11:59:34 AM »
Have you checked the site store first. Might come in a gasket kit also.

Offline blazer74

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Re: Taillamp Gaskets
« Reply #6 on: November 21, 2017, 12:04:08 PM »
Gm likes to change numbers, a newer model might show an updated #.
Hard to say if there available from Gm but reproductions are out there.

Offline ehjorten

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Re: Taillamp Gaskets
« Reply #7 on: November 21, 2017, 12:19:31 PM »
Where can I get them?
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline blazer74

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« Last Edit: November 21, 2017, 03:53:31 PM by blazer74 »

Offline blazer74

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Re: Taillamp Gaskets
« Reply #9 on: November 21, 2017, 03:52:14 PM »
Email or call the site store first

Offline VileZambonie

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Re: Taillamp Gaskets
« Reply #10 on: November 21, 2017, 05:09:30 PM »
The depiction posted above is for the gasket that goes between the lamp lens and the lamp housing even though the image is out of order. Do you have pics ? I've never seen a factory body gasket, not even sure what purpose it would serve if there were one or how it would seal anything. The closest thing I've ever seen to a gasket on the body side is a foam seal on the back of the vertical reflector and only on some of them. I have a surplus of 73-87 factory lights in my garage and none of them have a body gasket, only the lamp lens to housing gasket.

,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline ehjorten

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Re: Taillamp Gaskets
« Reply #11 on: November 22, 2017, 10:37:11 AM »
Vile;

I saved the factory housing and lens that wasn't broken.  I will take picture of the gasket on the back of the housing.  It is glued on to the back of the housing.  I tried to separate it and reuse, but found it was glued pretty good and didn't try that hard.  My rear taillamp harness was the problem with my left turn signal and brake lamp malfunctions.  I replaced that and put in new taillamp sets and it never worked better!
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline VileZambonie

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Re: Taillamp Gaskets
« Reply #12 on: November 27, 2017, 08:05:39 PM »
Vile;

I saved the factory housing and lens that wasn't broken.  I will take picture of the gasket on the back of the housing.  It is glued on to the back of the housing.  I tried to separate it and reuse, but found it was glued pretty good and didn't try that hard.  My rear taillamp harness was the problem with my left turn signal and brake lamp malfunctions.  I replaced that and put in new taillamp sets and it never worked better!
Did you take pics?

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,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline ehjorten

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Re: Taillamp Gaskets
« Reply #13 on: November 28, 2017, 09:40:55 AM »
The gasket is a closed-cell foam that appears to be about 3/8" in width and at least 1/8" thick, though likely a little more before compression set.

It was tack-glued on in the 4 corners of the housing.  The replacement Depot lamp housings have the raised perimeter on the back of the housing that the gasket fits around.







« Last Edit: November 28, 2017, 09:43:36 AM by ehjorten »
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline Henry

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Re: Taillamp Gaskets
« Reply #14 on: November 28, 2017, 12:28:20 PM »
Hi EH:
You know, that outside gasket sure looks like a professionally made gasket that is supposed to go on the rear lamp assembly. I would guess that it is OEM as the parts book show. The lens to housing gasket is not shown because it is automatically included when you buy the housing and not considered a separate part. Why does the front lamp have a separate part number for the lens to housing gasket?...good question.

You know, when I first painted my 76 C-20 25 years ago, I recall there also being this external gasket when I disassembled everything...but mine is gone now as I have bought replacement assemblies without the gasket, and as Vile has mentioned it all fits OK. Maybe the factory supplied this gasket to make the rear lens assy fit better to the body as it fits around a curve...I think it is possible to crack the assembly if you tighten it too much on this curve of the bodywork or scratch the paint on the curve of the body. The front lens assy is flat and so there is not a tolerance issue on fit to the body. Over time, the aftermarket guys just leave off the gasket because it only solves a tolerance issue that rarely comes up and makes the product cheaper. That's my guess on the situation.