willysmjeeps.com

This question was emailed to me and I decided it needs to be here so all can benefit from it's answer.

Tried doing a search on the regular jeep sites "willysmjeeps" and such but have not located what I am looking for or maybe I don't know how to make the correct inquiry line.
   So here it is. Wes, can you please tell me about the Correct Drain plug for a 52 Willy's M38 and maybe send me a picture of one? This is the one that goes in the bell housing and is supposed to be kept in the glove box... yep, I know you knew that, but I am just trying to cover the bases for explaining it.

This is a good question and it is a good candidate to be asked on the mjeeps tech forum where the entire group can learn something from the answer. So I will post your question there.

The short answer is in the ORD 9 SNL G-758 dated 1955 and it's related -20P for the M38A1. I could not find it listed in the M38 ORD 9 or ORD 8 . There are two listed: one is cast iron square head 1/8" P plug 103865, H006-0283566, 4730-278-3389 and the other is steel 103877 or H006-0283956.

Is the bell housing plug pretty much the same pipe plug as you can pick up in a hardware store? Seems like Willys used a lot of off-the-shelf hardware anywhere they could.

Yep

Of interest, I have seen many Marine Corps M38A1s that had a 1/8 pipe end cap mounted to the inside of the glove box door with the pipe plug threaded into it for easy access. A hole is drilled through the cap and one in the glove box door and attached with a short slotted machine screw mounted about the center of the glove box door. The Marines are the only ones I know that use this method to keep up with the bellhousing plug. When you see a M38A1 with this modification, its more than likely a Marine Corp M38A1.

That's a good piece of Info Harold. Thanks.

I think it is 1/4 plug, at least per http://willysmjeeps.com/downloads/M38.U ... .12.04.pdf

Hi Badlion,
That's a typo. It's a 1/8th inch plug.
See the parts list on the last page of this link: https://cj3a.info/sibling/m38vent/vent.htm

While not always necessary, it's often beneficial to independently verify (with two or more sources) almost any bit of information with these old jeeps.
Especially before buying expensive parts.

There's errors and typos in the Army manuals (which is bad enough), but many interweb "sources" and forums are also rampant with errors and mis-information.

Like a wise man once said: "Trust, but verify."

Welcome to the forum!
You have a M38?
Post a photo for us!

1/8 is the nomenclature for the plug. It's actual measured diameter is 1/4". However if you were to order a 1/4" drain plug you would receive one that is twice as big and won't fit!

Yes, it is a 1/8” NPT or National Pipe Thread plug.

The dimensions of various pipe, tubing and other threaded fittings don’t always equal each other. Some have dimensions which refer to the external diameter and some to the internal.

Fortunately in this case it’s your standard hardware store pipe thread fitting, or 1/8” NPT.