M38 : OK, Boomer

RonD2 · Post by **RonD2** » Thu Mar 17, 2022 4:28 pm

Sure thing Don.
Take the lid off your canister. With your lid being marked "Military Standard", I don't think there's any doubt about the diameter of your canister being correct, but just in case, my can measures almost exactly 5-inches in diameter (outside edge to outside edge).

Still without the lid on, mine measures almost exactly 6-3/4 inches from the top edge where the lid sits to the bottom of the boss where the lower brass fitting for the return hose screws in.

Measured with a steel machinist ruler and my eyeballs. Hopefully how I described these measurements are clear. Your wood ruler is very nice too. I use mine for lumber.

Can't help with Military Senior measurements. I don't own one. Pretty sure the maker marked the lids "Military Standard" without "Junior" or "Senior" to keep them interchangeable.

Let me know if you need anything else. Always glad to help when I can.

Naugha · Post by **Naugha** » Thu Mar 17, 2022 8:09 pm

Thanks Ron. So..... (fingers crossed).
It’s a ‘Junior’ and if I resolve the tight fit issue, then this puppy can stay?

That fizz you hear is the PB blaster working it’s magic on the bypass plug.
Put a third and final coat of paint on the tub today. Slick.
Added the ‘dzus’ (sp) brackets that hold the cowl BB lid.

RonD2 · Post by **RonD2** » Thu Mar 17, 2022 8:31 pm

Sounds like it can stay to me.
No Generator on mine so I can't help with your tight fit issue.

Maybe one of the other members here that runs a stock M38 24V system can provide a photo or two of the clearance between the bottom of the Junior and the Generator.

I haven't searched the manuals or member galleries for revealing photos.
I assume you did.

Post by **wesk** » Thu Mar 17, 2022 10:56 pm

Sure doesn't look like the Mil. Junior in the illustration.

Another important issue with determining for sure which one it is are the multitude of different elements used.

Naugha · Post by **Naugha** » Fri Mar 18, 2022 6:02 am

I do try to look up stuff but often end up chasing my tail. Here are some things that have me scratching body parts about oil canisters. Not saying the following is all true. Just saying it’s unclear to me. Random thoughts.

* Do any of the various oil canister diagrams give dimensions?

* In some old G503 threads the ‘Senior’ can is described as having the same diameter as the ‘Junior’ (same top/lid) but being almost twice as tall with a 8”+ filter inside.

* My filter element which fits was purchased from a vendor who listed it as for the M38..... need to look that up & send a pic.

* Does Ron have the same size oil canister as mine? If his is close to what the rulers show for dimensions then ???? is his a Junior?

* Fram vs Purolator. Were both used as replacements for the cuno?

* How much clearance should there be between the bottom elbow fitting of the can and the big generator elbow cannon plug .... assuming I have the generator correctly installed.

Xamon · Post by **Xamon** » Fri Mar 18, 2022 8:52 am

Just my thoughts here.

If the base of the junior and senior are the same and the bottom bracket is at the same height respective to said base then there should not be a clearance issue at the bottom, the filter should just stick up past the top too far.

RonD2 · Post by **RonD2** » Fri Mar 18, 2022 9:05 am

Xamon wrote:If the base of the junior and senior are the same and the bottom bracket is at the same height respective to said base then there should not be a clearance issue at the bottom, the filter should just stick up past the top too far.

Not sure I understand what you're saying Xamon. The canister can be set and clamped at most any height using the two strap-clamps.
Pretty sure it can be set high enough in the clamps that the hood won't close without hitting it.
And it can be set low enough to hit the Generator.
It definitely has a sweet-spot for where to mount it in the clamps.

Here's the filter element I use. Fits perfectly. https://www.ebay.com/itm/111751870054?h ... SwNSxVDbcB

I agree with Wes, it sure looks like it's not a Junior.....some kind of optical illusion. The machinist rule doesn't lie.
In Don's photo that Wes quotes, Don does have it mounted in his "Bubba bracket". Maybe that's the source of the illusion?

Post by **wesk** » Fri Mar 18, 2022 10:26 am

Before we overthink Don's dilema perhaps it is time to see what length generator belts he is using. Too short EQUALS Generator sitting too HIGH. Also are the generator pulley and the crank/waterpump pulleys alighned properly?

To answer Don's other questions:

* Do any of the various oil canister diagrams give dimensions?

No. I do not have any junior photos with dimensions.

* In some old G503 threads the ‘Senior’ can is described as having the same diameter as the ‘Junior’ (same top/lid) but being almost twice as tall with a 8”+ filter inside.

Have you read all the pages of the oil filter posted in my Oil Filter Sub-Album?

* My filter element which fits was purchased from a vendor who listed it as for the M38..... need to look that up & send a pic.

earlier you mentioned buying the oil filter from a vendor and just now you mentioned buying the element from a vendor. This forces the question did you buy both from your vendor or did you already have the filter assembly before you ordered the element?

* Does Ron have the same size oil canister as mine? If his is close to what the rulers show for dimensions then ???? is his a Junior?

* Fram vs Purolator. Were both used as replacements for the cuno?

Actually both Fram & Puralator made the military junior for the Army and their slight differences are mentioned often in many posts.

* How much clearance should there be between the bottom elbow fitting of the can and the big generator elbow cannon plug .... assuming I have the generator correctly installed.

Bottom line is simply NO CONTACT!

Finally is your bracket correct for an M38's L134 and a Military Junior?

RonD2 · Post by **RonD2** » Fri Mar 18, 2022 10:43 am

Don's photo shows the canister mounted using his "Bubba bracket" that he made while doubting he has a Junior (see my arrow).
Hopefully it's gone by now.

Naugha · Post by **Naugha** » Fri Mar 18, 2022 10:57 am

The belt length being too short..... ahh, that would explain the problem.
Will go back and see what I bought.

Here is the ad description of the belts.

“This is a brand new set of matched fan belts. These are for the M38 and M38A1 using the two groove pulley water pump, original crank pulley, and generator. These are matched so they are identical in size and length. Yes, these work with the 134L and 134F motors as long as the original military parts listed are being used. Please see pictures, thank you! QTM Parts”

Would such belts eventually stretch enough to give me 1/2” more distance below the bottom of the oil canister ?

In my early pic of the mounted canister it does look very long. Camera angle ?

If measurements mean anything here:

* The ‘zero’ mark of the wooden ruler is even with the bottom of the canister not counting the lower nut/bolt head.
* The height/ length of the canister (not counting top nut/bolt) is just shy of 7.5”.

The oil canister came with the jeep. I tossed the old element that was in it. Here is the ebay ad for the filter element I bought and installed but I need to go back and see if the element really fits my can properly... I think it does.

https://www.ebay.com/itm/301894416287?h ... SwvgdW4d6-

I spend a lot of time looking at the albums/sub albums but am still frequently surprised about something I did not see, did not understand or just forgot. I also check old threads here and other places. Amazing how many different ‘opinions’ one can find out there

RonD2 · Post by **RonD2** » Fri Mar 18, 2022 11:18 am

Don,
Where do you have the Generator belt tension adjusting arm bolted on the motor?
There's a dedicated hole and bolt for it on the front motor plate.
Can you give a photo or two of the Generator mounted?

My Junior -- canister only -- is 6-3/4 inches tall (without lid or bottom brass fitting).
Is that what you measure?

I use the same AC-P115 filter element. Fits perfectly.

Naugha · Post by **Naugha** » Fri Mar 18, 2022 11:40 am

Ron.

I think my can is about 7 1/2” tall not counting the top/bottom bolts but tomorrow will triple check my measurements. Am I correct in thinking there is little ‘official’ documentation showing the dimensions of the Junior/Senior military oil canisters..... just diagrams that lack the dimensions??

Will take recon pics of the terrain that may help reveal problems.

Diagrams from the TMs and M38 pics from the albums help guide the reassembly, sometimes watch a G503 or Metalshaper video.

Simple. Right? What could possibly go wrong.

Short belt length would explain a lot.

RonD2 · Post by **RonD2** » Fri Mar 18, 2022 12:20 pm

I've never seen any authoritative measurements for the Military Standard canisters (tech manuals, etc.).
Because Wes said the same thing, I believe it and quit looking.

Which leaves just us girls to compare what we have.

Like I said, mine (without lid or bottom brass fitting) is 6-3/4 inches tall.
So it's important for us to compare apples-to-apples with the ruler. Your measuring with lid on is apples-to-oranges.

I'll dig out my other packaged Junior (for the spare motor) and measure it. If it's different I'll let you know.

Anxiously waiting for you to find a published source for "correct" belt length.
Here's a 10-year-old post to get you going: http://willysmjeeps.com/v2/modules.php? ... elt+length

RonD2 · Post by **RonD2** » Fri Mar 18, 2022 2:06 pm

Don,
Both my Junior canisters, side-by-side, are identical and measure 6-3/4 inches tall (no lid, to the bottom of the lower boss).

I amended my previous posts that said 6-5/8 (off by 1/8-inch).
I re-calibrated my eyeball and used a different machinist ruler.
Apology for the error.

Naugha · Post by **Naugha** » Fri Mar 18, 2022 3:59 pm

My canister without the lid measures 6 1/4" tall,
but when you factor in my age, eyesight and IQ... it could be more like 6 3/4"

Also there is this:
Looks to me like the filter element fits.

Without the Bubba Bracket the lower brass elbow touches the generator cannon plug .... needing a few mm to clear.
But with the BB you get this.

The outside belt circumference is 46 1/4" with what looks like proper tension. I didn't do the tension / belt deflection test.