Hodakaguy M38 Misc Thread

HodakaguyTom · Posted: Sat May 04, 2024 5:49 pm Post subject:

Getting this baby ready to play with...

First up is to clean up both battery boxes. The Jeep came with the correct 2HN military style batteries installed, these are wet cell lead acid batteries and sitting for years hasn't done the battery boxes any favors. Luckily the corrosion wasn't to bad so we set to getting them cleaned up and re-painted.

We will be replacing the 2HN batteries with sealed 51R batts, I've had great luck with sealed batts over the years and the lack of corrosion alone will make the swap worth it. This is a practical swap that doesn't modify the actual Jeep, if someone wanted the correct batts it would be a simple swap back.

The batt compartments as purchased. Sitting in the garage for years didn't do them any favors.

Front batt box removed, Baking soda and a good scrubbing to neutralize the acid on both boxes.

Cleaning up the base and internal batt boxes.

Sandblasting the smaller bits.

A couple coats of primer applied.

The new 51R sealed batts are about an inch smaller than the 2HN batts. I was going to fabricate my own hold down brackets then found these cool brackets for sale, custom made for the 51R's. Nice!

And in primer.

And in paint.

Still wet so the color is slightly lighter since it hasn't dried yet.

Time to flush and bleed the brakes. The master cylinder is located below the drivers side floor and the cap is vented up to the air filter assembly under the hood (Part of the fording capabilities of the M38). These Jeeps were set up to use DOT5 fluid, the fluid in this one looked clear and not purple (DOT5 is purple) so I flushed and installed DOT4 since it looks like that is whats already in there. All 4 corners were flushed and bleed. Also adusted the free play on the pedal to 1/2" and adjusted the brake pads on all 4 corners.

Making a custom bent 1/4" wrench for the rear brake bleeders.

Front and rear axles were drained and re-filled with fresh fluids. I'll be draining and re-filling the transfer case and transmission with GL4 soon.

Hover Jeep lol. Pic was taken before the rear jack stands were installed....I'm not going under without 4 jack stands!

Filling the front knuckles. I'm using JD Cornhead grease, this grease is between a grease and an oil...It's thick enough that it doesn't leak out like 80w-90 and thin enough it properly lubricates and circulates unlike regular grease that just sticks to the inside of the knuckle housing.

I heated the grease up with a heat gun a bit and poured it into a oil syringe, the syringe worked great for squirting the grease into the knuckle.

As you fill the knuckle turn the hubs over by hand as you fill. This will get the grease all the way around inside the housing and allow you to completely fill the knuckle to the bottom edge of the threads.

More to come.....

Hodakaguy

HodakaguyTom · Posted: Sat May 04, 2024 5:52 pm Post subject:

Getting a bit more progress in.

Up early and changing out the oil pressure sending unit. The unit was acting weird during the short time we were driving the Jeep, the gauge would randomly quit then show pressure when the engine was off after the key was cycled. It's a good thing I have Go Go Gadget Arms as removing the sending unit is an exercise in dexterity. The new unit was just slightly smaller in diameter so I added a thin piece of neoprene rubber between the sender and bracket for a secure fit.

Drained and re-filled the transmission & transfer case with Redline MT-90. I've found in my older vehicles that MT-90 works great and usually improves shifting. The oil is GL4 and safe for yellow metals. The old oil was nice and clean.

Time to change engine oil. I drained the oil through a clean cloth to see if there were any bits or pieces that shouldn't be there, nothing was caught on the cloth. The oil was defiantly dark and ready to be changed. We ran a magnet through the oil to see if there were any metal fines present...nope, nice and clean. I'll clean the oil filter assy and air cleaner soon.

Fresh oil going back in. In my older vehicles I like to run either Valvoline VR1 or Mobile 15w-50. Both of these oils have higher levels of Zinc for push rod and flat tappet engines. I've always had great luck with these oils so decided to use the VR1 in 10w-30 in the M38. I know oils can be a hot topic....for me these two have always been my go to oils for vintage engines.

LOTS of zerk fittings to grease. Only took one pic of the process though, transfer case shift linkage.

Rubber shoes going back on. I torqued the lug nuts to 3A specs at 60 ft lbs.

Getting a couple coats of OD on the battery tray and outer lip on the cowl battery compartment. Paint is light here as it's still wet.

I will paint the inside of the box after the edges dry completely.

Under hood batt box completed, freshly painted inside and out after a full sand blasting.

More to come....

RonD2 · Posted: Mon May 06, 2024 1:33 pm Post subject:

Magnetic oil drain plug would probably be easier to see and less messy?
Several available on the aftermarket for the L134.
Can't tell the difference when installed.

I also have them in my transmission and transfer case.

And if you want to know the nitty-gritty, take a sample and send it off for analysis here: https://www.blackstone-labs.com/
_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

HodakaguyTom · Posted: Tue May 07, 2024 7:15 am Post subject:

oilleaker1 · Posted: Wed May 08, 2024 3:09 pm Post subject:

Congrats on about as nice a M38 as they get. The Jeep went to the right home.

Your FJ made me grin also.

You probably got mobbed at every gas station on the way home. (I don't know, I just bought it Laughing

) Some guys end up with a enclosed trailer just to stop the 20 questions so they can get to their destination. I had a guy that insisted on trading his BMW new motorcycle for my 1943 GPW in Cheyenne one time.

Thanks for the pictures, Oilly

HodakaguyTom · Posted: Thu May 09, 2024 10:55 pm Post subject:

HodakaguyTom · Posted: Thu May 09, 2024 10:55 pm Post subject:

More progress....

Cowl battery box interior painted. Bottom holes are still taped over from painting in this pic.

Even though we are installing sealed batteries I went ahead and added a battery mat under each battery. The battery mat adsorbs and neutralizes any acid that it comes in contact with, it also adds a bit of padding between the battery and the tray.

Cutting the mat to fit the battery tray.

Tray re-installed.

Front battery box mounting plate freshly painted and ready for the battery box to be re-installed.

Trimming the battery mat for the front battery tray.

Adding some NCP2 corrosion inhibitor to the terminals.

That's much better!

Cleaning the Cuno oil filter. The oil filter on the M38 is a bypass unit, meaning only a slip stream of oil goes through the filter. Two different types of filters were used on the M38's, a Cuno filter (Pictured on our setup) and a cartridge style filter.

Since we just purchased the vehicle we removed the filter assembly from the jeep and disassembled it for a thorough cleaning.

The filter works by pushing oil through the tightly spaced disks. To clean the filter you rotate the handle on top of the filter and it turns the disks and combs the disks to remove any debris that have been caught. The debris falls down into the settling bowl where it can be drained out by removing the plug on the bottom of the bowl or disassembled for a full cleaning.

Assembly cleaned.

With the oil filter re-installed we removed the drain plug on the bottom of the filter and cranked the engine over without starting it to ensure we have oil flow/pressure. Oil quickly drained from the filter assembly indicating the oil pump is working like it should be...perfect! The oil looks dirty here as we basically flushed the old oil out of the oil lines in this process.

Next up was to clean the oil bath air cleaner.

Removal is pretty quick. Remove intake and snorkel hoses.

Then remove the vent lines attached to the rear of the filter housing and remove the filter assembly.

To clean the filter remove the lower oil bath reservoir, drain and clean the unit out.

Then remove the internal screen cartridge from the main filter assembly. This unit is full of a wire wool material. Flush this unit with gasoline or solvent then blow dry. Refill the unit with fresh oil and re-assemble.

Installing a new snorkel hose. The original snorkel is starting to crack and is needing replacement. With a new hose in hand its time to swap it out.

Out with the old.

Old vs New.

And new installed.

Drained the ancient fuel out of the tank and wiped the bottom out, then put in 5 gallons of fresh ethanol free fuel.

Received my small rechargeable speaker today for the Jeep. I saved an audio clip of some military artillery radio chatter to an SD card then installed the card in the speaker. Now we can hide the speaker under the radio in the back of the Jeep and when people are walking around it at shows they will hear radio chatter that seems to be coming from the Jeep's radio unit. Pretty cool effect.

Here's a quick video of the speaker in action.

CLICK HERE: https://youtu.be/rZdOyywWppU?si=RW8PokpCoPylTnzW

Now we are waiting on our carburetor diaphragms to arrive and a few other small bits.

More to come.....

Hodakaguy

Beast · Posted: Sat May 11, 2024 11:23 am Post subject:

I do something similar at displays. I use an old iPhone that I had around and downloaded several radio chatter files to it and let it play during shows. It's slim and can easily slip under the radio mount and really does make it sound like it's coming from the radio. I have it set up on a loop and it's about 3 hours total. I also gutted on old transistor radio and added a speakers and MP3 player and play period armed forces radio broadcasts. It really helps bring the display alive.
_________________
Dave
53' M38a1, 53' M37, 67' M715, 67' M725, 67' M35a2
http://www.davidallenracing.com/motorpool.htm
Delta Team Decals http://www.deltateamdecals.com/

HodakaguyTom · Posted: Sat May 11, 2024 9:21 pm Post subject:

HodakaguyTom · Posted: Sat May 11, 2024 9:22 pm Post subject:

Someone pointed out that our hand throttle and choke knob are swapped in each other's positions. Time to make that right.

As we picked it up.

HodakaPops getting some seat time in .

Cables out.

All finished.

Hodakaguy

RonD2 · Posted: Tue May 14, 2024 3:04 pm Post subject:

_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

HodakaguyTom · Posted: Tue May 14, 2024 9:09 pm Post subject:

A little carb work today.

When we purchased our M38 the Jeep was having a rough time running, blowing black smoke, stumbling and running super rich. It was barely drive-able. The Jeep has been sitting for years at this point so we expected a few make run issues. We changed out the ancient fuel (yellow varnish at this point) with some fresh ethanol free fuel and..... it ran even worse! Sooooo we ordered up a carburetor kit and today set to see what we could find.

The Carb before the disassembly.

Popped the elbow off the carb, the bowl isn't as bad as I thought it might be. Wiping my finger in the bottom of the bowl showed a film of greenish sludge.

Removing the metering rod diaphragm. Not in the best of cond, it's cracking and more than likely leaking.

Removed the entire carb from the Jeep and moved it over to the work bench.

Disassembly.

Main fuel strainer looked clean.

Running parts through the Ultrasonic Cleaner. This machine does a great job at cleaning all the internal passage ways.

Interesting find. The original metering rod was missing the pin the connects the metering rod to the diaphragm, the metering rod was just floating around loose. Well that's not good!

New assembly.

Going back together.

Float height as found was off, a quick re-adjustment returned it to spec.

More Re-assembly

The engine starts and runs smoothly now with no smoking. Power/ acceleration is a bit lower than I would expect but I haven't tuned the carb yet, checked timing, valves etc...I'll be doing that soon.
I wish I would have measured the metering rod to verify the kit came with the correct rod for the M38 and not the M38A1, I may end up pulling it back out to double check.

Took a drive around the block with the kiddo and put it back to bed till the weekend.

More to come...

Hodakaguy

RonD2 · Posted: Tue May 14, 2024 9:43 pm Post subject:

The Army issued a MWO-TB to re-route the carb fuel line away from the exhaust manifold to avoid vapor lock.

_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

RonD2 · Posted: Tue May 14, 2024 9:49 pm Post subject:

Don't have snorkel and snorter tubes on mine, but recall reading threads in the forum saying they can rob power when left installed constantly.
Might be a tuning issue?

Just a thought.

Great photo journal of what you're doing!

Good luck!
_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

RonD2 · Posted: Tue May 14, 2024 10:45 pm Post subject:

Also happened to notice the thick carb base gasket you have isn't the M38 "diffuser" type called for in the September 1955 edition of the ORD9 Manual (page 68, WO-A923, G740-7372543), designed to help atomize fuel flow to the intake and insulate the carb from manifold heat.
Shown here:

_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari


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