floor drain covers

BCA · Post by **BCA** » Tue Aug 27, 2019 10:21 am

Been fooling with my M38 floor drain covers: from observations of original examples were the rivets holding the rubber gasket on the lower side of the cover or on the upper side. I suspect the original intent was to have the rivet heads on the lower side with prongs facing up. But I have seen both variations. Incidently the Canadian parts book and microfiche say the gasket was natural rubber, 3" long x 1-1/4" wide x 1/16" thick with two 1/4" holes and one 3/16" hole.

4x4M38 · Post by **4x4M38** » Sat Aug 31, 2019 8:52 am

Rivet top down. The prongs are bent up into the rubber, like the gas tank rattle strips.

45auto · Post by **45auto** » Sat Aug 31, 2019 1:04 pm

Brian,
What you bring up with the drain plugs is interesting. As shown in the manual the intent as you said, was to have the rivet head down. The real question is, did any come from the factory with the rivet head up. However, there are not very many original M38s that can be sampled to see just how they could have came. If it helps any, on my original M38, 68468 May 1952, they are rivet head down. I would think if there was any kind of inspection on the assembly line, this would be caught and corrected. But, who really knows?? With replacement parts the person who assembled the drain plugs could easily reversed the order and they were then installed as they came packaged by the military.

With that said, if I open up a set of NOS drain plugs that came with the rivet head up, I would use them as they came. For a factory restoration I would install them as the manual shows as that would be the only proof that is how they were to be installed.

Thanks for bringing up another interesting tidbit on the M38.

Harleygaz · Post by **Harleygaz** » Sat Aug 31, 2019 1:55 pm

Floor drain plugs are new to me. May 52 M38. Could you post pics so I can what they are and where they were installed please?

Post by **wesk** » Sat Aug 31, 2019 7:26 pm

Here's a photo of Midwest Military's replacement drain covers with pivot screws and rivets for the rubber seals.

4x4M38 · Post by **4x4M38** » Sun Sep 01, 2019 7:00 am

Harold,
Thanks as always for your remarkable database as well as Wes’ photos

Thinking about this a bit more I don’t think it makes sense the rivets would have been installed pointing up. Pointing down the rivet ends when squeezed into the rubber would depress into the rubber, hopefully far enough to prevent scratching the floor paint and giving rust a toehold. Pointing up I think the rivet heads would not sit down into the rubber far enough and would “ride” on the floor, damaging the paint.

Just my two cents.

Post by **wesk** » Sun Sep 01, 2019 10:47 am

Just my two common senses! With the rivet tails down they are much more likely to loosen and catch on the edge of the floor holes when they are rotated hence the smooth round heads will not be effected by an occasional bump into the edge of the floor holes.

45auto · Post by **45auto** » Sat Oct 05, 2019 8:56 pm

I recently pick up an NOS Drain Cover for the M38 and M38A1. It was made 10-56 and has the paper info tag on it and the manufacture name and part number stamped on the bottom. However, its missing something!!!

Check my album to view the Drain Cover pictures as I can't seem to be able to master posting pictures.

Soooo, what's the deal. Just another variation on the parts the military buys or did Willys or the Military decided it didn't need the rubber gasket?? The question is to show anything is possible. Nonetheless, it was an interesting find.

Post by **wesk** » Sat Oct 05, 2019 9:51 pm

Hello Harold,

However, its missing something!!! Soooo, what's the deal. Just another variation on the parts the military buys or did Willys or the Military decided it didn't need the rubber gasket??

Actually what you received was what you ordered. ORD # 7697520, WO# 674364 is for the bare cover only. ORD# 8677314, WO# 674408 is for the cover with gasket assembly!

45auto · Post by **45auto** » Sat Oct 05, 2019 10:09 pm

I didn't point it out---but the two small holes to attach the rubber gasket is not drilled in this Drain Cover!! I seen in the parts manual where you can or could order just the rubber gasket depending on what you needed. I can't help but wonder if by this late date if it was decided that the Drain Cover would fit tight enough to do an acceptable job. Hence, you wouldn't want the two rivet holes. However, its just a guess and it could be as simple the manufacture missed punching the holes and the military overlooked it.

Its still interesting this manufacture didn't punch the holes to attach the rubber gasket and opens the question as to why.

RonD2 · Post by **RonD2** » Sat Oct 05, 2019 11:17 pm

I've wondered about those rubber gaskets myself. Seems to me the truck body was never intended to be waterproof in order to float (like the M100), so why rubber gaskets? Especially with the several other smaller open drain holes in the floor pans.

I was thinking these two drains (each with two one-inch holes) were there mainly to allow larger debris and water (mud) to quickly flush out of the body --- they were never intended to keep water out.

Just my rookie 2 cents!

RonD2 · Post by **RonD2** » Thu Apr 08, 2021 7:18 pm

Not mine, but thought I'd share these photos I came across in my research that appear to show original M38 floor drain cover rivet heads on the top side of the covers rather than on the bottom.

Reading this post I got confused (like I easily do) about the description of the rivet head being "up or down" --- perhaps saying the rivet head is on the top (side) of the cover --- or the bottom (side) of the cover might clear things up? Does for me anyway.

You'll probably need to zoom in on the cover to see what looks to me like rivet heads on the top side of the covers.

Hope this helps.

RonD2 · Post by **RonD2** » Thu Apr 08, 2021 7:50 pm

By the way, I bought a pair of NOS drain covers in original packaging dated 1953. One cover had pre-drilled rivet holes and the other didn't (they weren't in the same package). Neither has part numbers stamped on them.

I installed both on my M38 without the riveted rubber gasket. I know the rubber gasket and rivets are listed in the ORD9, but there seems to be some question if the rubber was eliminated at some point? I figure can always drill the holes in the one and put them on later if I get the bug.

Post by **wesk** » Thu Apr 08, 2021 9:47 pm

The only final word on this can be found on the factory original blueprints. Maybe Keith has this blueprint. The published date of the ORD 9 (1955) makes it obvious that the rubber gasket was still in use 3 years after the M38 finished production.

WillysMotors · Post by **WillysMotors** » Sun Apr 11, 2021 11:51 am

I'll put this on the list of items to research when I return from Pearl Harbor eventually.