Topic: 1937 taillight lens fit problem


BRL    -- 08-31-2022 @ 9:29 AM
  Hi Guys:
I have a 1937 model 78-750, no customization. The taillight lenses have a loose fit. I have disassembled them and it is not apparent to me what the problem is. The lenses dont seem to register on the lens housing in any way before you snap on the retainer. I have some questions that I hope people that have had the same problem as me can possibly answer:
1. Does the gasket go between the lens and the housing or between the retainer and the lens?
2. Is this looseness caused by aftermarket parts(retainer, lens, gasket) that dont fit as well as OEM?
3. What are the correct Ford part numbers for the lens, gasket, and retainer for my 78-750 model (I have 2 taillight pods and the lenses are red) ?

Thanks,
BRL


1937sedandelivery    -- 08-31-2022 @ 9:41 AM
  Hello,
I have a 37 Fordor Deluxe. Attached is an exploded view of right rear taillight.
gregg


same    -- 08-31-2022 @ 11:47 AM
 
hey BRL,i too have a '37 be oit a fordor of course with same tailights. i dont care for the way henry designed the tail lamps. in the early 80s i owned a model A street rod with period correct tail lamps. better set up. with these '37 tails iv'e had to bend the little metal retainer that the mounting screw goes into. put a thick padded bedspred under the assybly if on concrete or park in grass. i wish the made plastic oe lenses. Tom.


BRL    -- 09-01-2022 @ 7:57 AM
  Hi Guys:
Thanks for the info and especially the very nice exploded parts image, Gregg. The existing lenses, door, and gasket I have on my car I believe now are aftermarket parts. The parts I have recently bought are the same so I am going to return them. I have ordered NOS lenses, door, and gaskets from Southside Obsolete and so I will see how it all fits when I get the parts. Having said that, I have a hard time understanding how the stack up of door, lens, and gasket(retainer) creates a water splash seal considering the door retaining tabs press radially against the door as you tighten the screw instead of pressing axially against the door/lens/gasket which is what I would expect to do to make a water splash seal....maybe the tolerances are supposed to be such that when the door is tightened radially it bends axially to squeeze against the gasket...?!? If I get all the NOS parts and the fit is no better I guess I will think about adding some custom cut gaskets or o-rings to the assembly...
Regards,
BRL


JayChicago    -- 09-01-2022 @ 11:01 AM
  I also found the '37 aftermarket gasket/lens/door would not tighten up. Lens rattling in there. Not sure which side of lens is proper place for gasket. Tried to put duplicate gaskets on both sides of lens, but that was too thick. Was able to fiddle with it and get the door a little tighter; seems as it pulls down on lens it also squeezes the lens/gasket a tad. Good enough, living with it.

Will be interesting to learn if NOS parts are any different. Maybe the lens glass is thicker. But I suspect it won't be any better. I suspect it's just not the best-designed assembly Ford ever made.


BRL    -- 09-27-2022 @ 8:18 AM
  Hi Guys:
I think I have found the reasons why I have a taillight lens/gasket fit problem. It all has to do with the poor quality of the aftermarket lenses and gaskets available.

-The OEM Ford lens, 78-13450 and 40-13450, has a small lip on the ID of the gasket sealing surface. This lip registers the lens on the lamp body mating edge for the lens. This keeps the lens centered on the lamp body. I have 2 different manufacturer aftermarket lenses and neither of them have this lip. Fortunately I found some NOS Ford lenses.
-The OEM Ford gasket , 78-13461 and 40-13461, is not available for sale anywhere as far as I can tell. So I cannot ascertain its exact dimensions as far as diameter or thickness. But it must be a minimum diameter of 2.750 inches (to fit over the lens registering lip), and a maximum diameter of 3.200 inches to fit inside the lens door, 78-13448. This size range also allows the gasket to seal against the sealing edge of the lamp body which is approx. 2.915 inches in diameter. So what are the dimensions of the aftermarket 78-13461 gaskets? OD=3.300 inch. ID=2.875 inch. Both dimensions are too big to work....the OD interferes with the door, and the ID almost falls off the lens sealing surface and edge of the lens door...since the gaskets are flexible they do fall off especially when they dont register on the lens lip.

So what am I going to do? I guess I am going to try and cut my own gaskets since I cannot trim the aftermarket gaskets to fit (I can trim OD but there is not any material in the ID). I am going to try to make gaskets with OD=3.125 and ID=2.770 with a thickness of .040-0.50 inch.

Regards,
BRL


JayChicago    -- 09-27-2022 @ 11:20 AM
  Ugh! Not a poor Ford design, is just another case of poorly made aftermarket parts. The glass lens is missing the lip that would keep it centered. The gasket is cut too big. Explains why I always had difficulty with this on my '37. Thanks for posting.


BRL    -- 10-20-2022 @ 9:09 AM
  Hi Guys:
I have made my own gaskets for the taillights on my car. Here are the dimensions I have used: OD=3.125" (3-1/8"), ID=2.750" (2-3/4"), and thickness .0625" (1/16"). I bought cork gasket sheet from McMaster-Carr that is adhesive backed, part number 9487K51 for about $10. I tried many thicknesses and .0625" was the thickness that works for me. Adhesive backed is the way to go because being then you can attach it to the lens prior to assembly without the gasket flopping around and not registering properly. So I cut my gaskets out as you see in the photo. Then I attach the gasket to the lens...see photo. Then insert lens and gasket into retainer and it all stays together...see photo. Then assembly to taillight pod. On my right taillight pod it fit perfectly...see photo. On my left taillight pod the lens was still loose. So I cut out another gasket and added it to the existing gasket on the lens to make a 1/8" thick gasket and then the assembly fit perfectly on the left taillight pod with no loose lens. I inspected all the parts and am not sure what was different, but this is what was required to be done to get the lens tight and the assembly water resistant. As a last commentary I will say that the step in the lens is so short with respect to the gasket that it does not play into registering the lens to the taillamp housing...it does help register the attachment of the gasket though. Once the gasket, lens, and retainer are all assembled it does not need any registering to the taillight housing...it pretty much self-aligns. Hope this helps anyone with the same problem as me.



JayChicago    -- 10-21-2022 @ 8:32 AM
  BRL: Thanks for taking the time to photograph and post all the details.


EFV-8 Club Forum : https://www.earlyfordv8.org/forum
Topic: https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=15917