1952 M38a1 Build: Not For The Purists

[jeepljeff]

Rescued this M38A1 out of the Santa Cruz mountains back in March of 2024. The funny thing is I saw this Jeep when it was with it's 3rd owner and was less than a mile away from my house maybe 2 years prior. Drove some 80 miles to get it. I was told by the 3rd owner that it was very clean, original and had very little rust. I was sorta looking for an old Jeep. '41-'75. I had driven a '46 CJ2A, a '47 CJ2A and a '60s CJ5. Out of those, I really liked how the CJ5 drove. The CJ2A's were more like sitting on a skateboard and didn't feel as planted on the road. So my friend "found" me a Jeep. He was the 3rd owner.

Here's some of the junk I got with the Jeep. There was a gas tank and two seats. Though the driver seat was cut up and used as a mount. Part of a Warn Overdrive which will come up later.

The first thing you see under the hood was the gigantic 6v gas heater on the right side. There's also a vacuum booster on the left side. They extended the reservoir with a tube so it's higher than the booster and would bleed properly. The carb was changed to a YF by someone.

After the second steam cleaning, some of the stenciled numbers started showing up. MI-30-58. I'm guessing the 58 is the year it was repainted red oxide before they sold it.

The block, I'm guessing is also a '58. It's newer than the Jeep. The block numbers should be lower than W-13.

Sanded down the bumperette and found some numbers. I still can't tell what the top numbers mean. The right most look like a 7 maybe. Then a 1 at the bottom.

One of the previous owners tried removing the Warn overdrive but took it apart wrong and left the output shaft just hanging out open for years, decades? Something else that's interesting is that the Jeep had a M38 transfer case. The transmission and transfer case for the M38 and M38A1 have noticeable differences from the civilian versions. The M38 used the civilian ebrake. I know it was done by the military in that they plugged the floor and the plug was painted red oxide. Also the transfer case have green paint under the grime.

Not only was the PTO plate off, the top of the transmission wasn't bolted down. The last owner tried to free it up with two bottles of Coke. Seeing what was actually, in there, there was no way Coke was going to free it. I poured some ATF in there to see if it would help. It didn't.

The cluster gear bearings were rusted solid. Same goes for the input shaft bearing. The transfer case intermediate shaft bearings were rusted solid as well. I was able to get them both apart and the cases cleaned up nicely.

Early on I decided that I wasn't going to use the gas tank. Someone tried sealing it and it was peeling off. I could reach into one chamber but not the other to tear it out. I heard I would use acetone but I didn't want to risk having problems with the tank. There didn't seem to be any rust holes in the tank which is good. I learned quickly that rebuilding a Military Jeep can be very expensive. Everything is 2-5x more expensive than the civilian version. I wanted to keep the 17 gallon tank so I bit the bullet and got the MD Huan repop.. Didn't have any problems installing it. I had more difficulty installing the 12v fuel sender than anything else. Quickly learned that those 5 holes aren't evenly spaced.

Also, I was given a driver seat frame but noticed someone cobbled it together and it wouldn't fit anymore. Luckily, there was the bottom portion of the old drivers seat that had the backrest cut off. I've been learning how to weld for the past year and was able to make one good seat out of the two.

These are the markings on the glove box on the Donor Jeep. A friend of mine just recently bought a 1960 CJ5 out of Oregon last month and then bought an M38A1 out of Portola Valley for parts. So I've been able to scavenge a lot of the small parts that mine was missing. I was also able to get the transmission and transfer case moving. Luckily, the transfer case just had the shift rails gunked up. This made the perfect donor for mine.

Steam cleaned the transmission and transfer case. Notice how clean the inside of the bellhousing is. I didn't have to do any cleaning there.

I've been waiting for over 2 months for parts from Kaiser Willys to rebuild my T90. I was running out of time as I'm losing access to the shop so the donor drivetrain couldn't come at a better time. Notice how it had a pull lever ebrake. The controller under the dash is for the gas heater and the box on the right is the vent.

One of the things my Jeep was missing was the 16x4.5" wheels. It had much later 15x7's, I think. Only one of the wheels were Jeep. The others seem to have been Ford. The Donor Jeep had the correct wheels. I think the military may have welded the lug nuts on! What a PITA to get those off. Also, having to deal with LH and RH threads is something new to me. A previous owner also swapped out the headlight buckets for CJ5. They were just stuff into the holes. I was able to get the one from the donor but it only had one outer bezel and I reused the CJ5 retainer rings.

Here's how it sits... on +60 year old dry rotted 7.00R16's. It looks good though. I'm keeping is stock height and with 7.00R16s. I'm also going to keep it unpainted. I was thinking that I was going to repaint it tan but after seeing it in person, I don't mind the pink. You can see Korea era forrest green and it's original OD green in many places. I'll probably use a scott pad and sand off more of the red. Oh and how do I know it's a '52? The Patent plate was still on it. Someone took the data plate before it was painted red. The Patent plate shows it was the 12xx M38A1 made. It has the M38 front bumper that the really early ones had. The '52-53's had the hinged grill and the screwed on battery box top. I have a 100A one-wire Delco and a Toyota Land Cruiser high torque starter. So it's getting a 12v conversion. The goal is to get it running and dependable that I can daily it. It doesn't have to be prefect. Much to the chagrin to the MV people, I don't have any plans on restoring it. I like the character it has. I'm hoping to sell off the 24v parts as well as the heater to recoup some money so I can put it back into the Jeep. One idea is to maybe take it on the 75th Jeepers Jamboree in a few years.

Hope to have some more updates soon.

Parts For Sale
https://www.facebook.com/marketplace/item/912575514311467
https://www.facebook.com/marketplace/item/1211243773310725
https://www.facebook.com/marketplace/item/1093209635840920

 

[homersdog]

Great write-up, looks like you have saved a good one!

 

[PeteL]

Very nice. Lots of good!

the gigantic 6v gas heater on the right side.

Six Volt? In a 24 volt jeep?

Here's some of the junk I got with the Jeep. There was a gas tank

I wouldn't call those tanks junk... Have you priced replacements???

These are the markings on the glove box on the Donor Jeep.

Looks like "20 MPH." Where would that have been the rule?

 

[jeepljeff]

Very nice. Lots of good!





Six Volt? In a 24 volt jeep?



I wouldn't call those tanks junk... Have you priced replacements???




Looks like "20 MPH." Where would that have been the rule?

Yeah, it's weird that it's 6V. I've only seen them used as a prop so that wouldn't matter too much.

I bought the repop tank so I know all too well how much they cost. One of the reason why the PO didn't build the Jeep was the cost of all the bespoke pieces and their cost. I might end up selling the gas tank.

Oh, it does look like it says 20 MPH. Not sure where the Jeep came from originally. It's number is 57xx. Maybe I'll post some pictures of it as well.

 

[PeteL]

it does look like it says 20 MPH

May say "On Base" if you were to keeping sanding.

 

[jeepljeff]

Here's some pics of the donor M38A1. This one is also a '52 but later 57xx. It was delivered on 8/52.

 

[jeepljeff]

I'm back at it. The HS Shop is closing for summer so the Jeep has to come home. Towned it home with a truck that's 30 years newer that the Jeep, yet 45 year old.

Got most of what I needed from the donor Jeep. It's looking pretty sad with the 15's on it. There's still some good parts on it though. The engine might be going into a '60 CJ5 that has a knock. I might also be grabbing an axle shaft from it. More on that later.

Got my Jeep towed across town without too much trouble. Turns out one of the rear tires is wobbling. Could be the wheel but it's also the same tire that was dragging the brake. I'm thinking the axle might be bent. Not a big deal since I've got friends with lots of spare axles as well as the donor M38A1. It also helps to have more than 9 psi in the tires when towing. At least I was taking it slow and look the long way through town so I didn't have to deal with any steep hills.

I've finally been able to inventory all the parts I have to put up a bunch of them on FB Marketplace.

• M38A1 Door Frames
• 24v VBC-4002UT Autolite Generator Regulator
• M38A1 17 Gallon Gas Tank
• 24V Delco-Remy 7355736 Generator
• 24v Auto-Lite IAU-4006 Distributor
• 24v Autolite MCZ-4001UT
• 6V Autolite GJP-7402-A Generator
• 6V South Wind 978-M Heater
• 24v VBC-4002UT Autolite Generator Regulator
• 24v Autolite GHA-4802 Generator
• 24v MCZ-4001UT Autolite Starter

I have this mystery generator as well. I think it's 6v but haven't gotten around to ID'ing it. Any help would be appreciated.

Spent a little time sanding the red oxide down to see what's under there as well. Would love to figure out what Unit it was in. I don't think I'm going to be getting anything off the hood unfortunately.

Also spent time time getting rid of some of the extraneous wiring and broken stuff. The heater is out but the harness to the dash as well as the fuel controller were still dangling under the Jeep. More stiff to sell though. Removed the broken choke cable as well as the broken throttle cable. I'll be replacing them later on.

It's nice being able to pop the gauges out with a 1/4 turn fittings to get behind the dash. THe hand brake cable was a real PITA. It was installed by the Military so they could use the M38 transfer case that they swapped in. I guess they had spare M38 parts so they just went with it. I've put the correct M38A1 ebrake in and have the proper handle. It's really interesting what the Military will do that's outside the box. At least they didn't hack the firewall up too bad to get the parking handle in there.

Don't ask me about the gauge colors. I don't know what that's about. Someone took the time to paint them though. The backside of the gauges were painted as well. They're all getting replaced with 12v gauges later on so it's not that big of a deal. I think the mileage is correct. THe first owner put some miles on the Jeep. But then the Jeep for a fresh new engine in '58. I removed the ignition as well as the cigarette lighter. Also, took out the turn signals. They were all wired into the 24v harness. The heater too. The first owner was living large with his gas heated hunting vehicle. I'm thinking that I'll cut the harness off the big connector on the light switch and put a deutsch connector on it so I can wire it with new wire. I'd like to get all of the blackouts working if I can. I haven't looked into how the switch is wired though. The main things would be headlights and maybe set up the blackouts like parking lights.

There's so much more room in the engine bay now. I still need to slot the hole in the starter a bit more so I can install the Land Cruiser starter. Then I'll think about what I need to do to get the distributor swapped. I need to pick up a 12v coil and mount too. There's still a lot to do.

 

[jeepljeff]

So, I've been putting in a few hours of work cleaning up the Jeep while I wait for parts.

Here's all that was removed from under the dash. Removed some unused vacuum (hard) lines that I won't be using. The Military had hardlines going everywhere and to everything. Since I'm not keeping the 24v, I won't be using the distributor so those vacuum lines going to it are getting pulled.

Because one of the vacuum lines was bolted to the back of the engine, I had to take some of the inspection covers off. What a PITA. At least it gives me access to the engine block.

Here's one of the quirky features of a military Jeep, kick switch for the starter. So instead of a key, you kick this plunger which pushes an arm on the starter solenoid. It's not going to be used since I'm converting to a 12v starter but I'll be reinstalling the foot switch.

To add some progress, I installed the ignition switch as well as the original power switch. I'm going to be replacing the power switch with a modern one so I don't have to deal with Packard and Douglas connectors. I think the empty hole is for the hand throttle. That was where the military put the parking brake handle for the M38 drum. THe hand throttle was originally under the light switch with the choke on the other side. I think the choke is supposed to be on the right side of the column. Anyone know what's supposed to be on the left side?

I'm also thinking about removing the vacuum booster that's cobbled into the Jeep. I'm not even sure if it works. I'll have to see how it's installed but if it's easy to remove I'll probably remove it. It's ugly and takes up a lot of room. Thoughts on that? I'm also trying to remove the main harness for the BO lights. That's the harness you can see behind the booster. I want to eventually put a deutsch connector on the other end so I can use the switch but with modern wires instead of Packard and Douglas braided cloth wires...

While I was cleaning, I also uncovered more rust that I though. Honestly, it's pretty minimal and should be easy to fix. The problem is Willys didn't put enough drain holes in the floors and it rusted through. Of course it's on top of the strengthening rib and seems to have rusted out a section of the rib. The good thing is that it too is pretty minor and only on the bottom. The sides seem strong still. So, I'll have to fix that once I'm done with everything else.

 

[Bob-The-CJ]

So all that 24V stuff is worth a fair amount of money - just letting you know. For example, that brake booster with a slave cylinder connector allows for pulling a trailer that is also 24V.

I swapped mine to 12V as well because, like yours, most of the 24V stuff was no longer functional or missing. I'm mentioning it just so you can look into it and consider your options.

It takes time to go through it all, but these Jeeps are simple to work on and it is in pretty decent condition.

 

[jeepljeff]

So all that 24V stuff is worth a fair amount of money - just letting you know. For example, that brake booster with a slave cylinder connector allows for pulling a trailer that is also 24V.

I swapped mine to 12V as well because, like yours, most of the 24V stuff was no longer functional or missing. I'm mentioning it just so you can look into it and consider your options.

It takes time to go through it all, but these Jeeps are simple to work on and it is in pretty decent condition.

Yeah, I've got a bunch of the parts listed for sale. I'm still not certain what it's all worth but looking at rebuild, NOS and take-offs I think I'm in the higher end of the ballpark. Problem is there's a small pool of people who want this stuff. I didn't even think about selling the brake booster though.


Parts For Sale

South Wind 978-M Heater
24v VBC-4002UT Autolite Generator Regulator
24v Autolite GHA-4802 Generator
24v MCZ-4001UT Autolite Starter
24v VBC-4002UT Autolite Generator Regulator
M38A1 17 Gallon Gas Tank
24V Delco-Remy 7355736 Generator
Auto-Lite IAU-4006
24v Autolite MCZ-4001UT Starter
M38A1 Door Frames
6V Autolite GJP-7402-A Generator​

 

[jeepljeff]

Spent the evening removing the vacuum booster. That was a bit of a PITA. It piggybacks on the standard master which is kind of a dumb setup. It really opens up the engine compartment though. I also removed the main harness some the Jeep. It's 72 years old cloth wire. It has the Packard and Douglas connectors. I'm hoping that they didn't hack up the brakes too much and that I can reattach the lines can call it good.

The pile of removed junk is getting bigger again. I need to reuse that large connector for the light switch. I did find that someone balled up the trailer connector and pushed it inside the body. I thought they had cut it off but I found it back in there when I removed the rear taillight. I'll need to rewire the blackout light housing with all new wire. I need to get a new high beam switch as well as the brake light switch, I think. The ones i have are designed for Douglas connectors. Next thing is, do I use the blackout taillight's or use the ones with the huge red covers?

Also buy my junk. I need to buy more parts.

 

[timsresort]

I'm all about being pure with the MV's, but if you think you are ever going to drive on a highway, go with full lenses. People can't see an OD vehicle, and aren't expecting someone to be travelling 45 MPH, when they are doing 75 with a phone in their hand.

 

[jeepljeff]

I'm all about being pure with the MV's, but if you think you are ever going to drive on a highway, go with full lenses. People can't see an OD vehicle, and aren't expecting someone to be travelling 45 MPH, when they are doing 75 with a phone in their hand.

Highways?! Yeah, I'll be staying off those till maybe I install an overdrive and even then. At least the Jeep's going to force me to discover all the backroads.

 

[jeepljeff]

Did a little bit of work on the Jeep. Installed the master power switch in the place of the Milspec. one. I haven't decided if I'm going to have it on the negative or positive. Might be easier to wire everything from the battery then run the negative to the cut off switch. At least the big switch fills the big hole that was left there for a cigarette lighter that once lived there. Cleaned up a set of the gauges even though I'm probably going to be replacing them. I was kind of surprised to see a chrome bezel on the speedometer and a copper one on the pressure gauge. I want to replace the amp gauge with a voltmeter. I'm going to need to replace all of the others since they use douglas connectors which I'm not using. Looking at how the lights work for the gauges I'm wondering if I should just upgrade with modern gauges that actually light up? The only hard one would be the speedometer as there aren't a lot of options for a 0-60 mph gauge. I've seen a 0-80 but most are 0-120. The two additional round holes are for the dash lights which shine behind the dash. The gauges have slots around the base of the gauge face where light leaks in and illuminates the face. Kind of a convoluted way to light the gauges up though.

 

[amboynut]

I haven't decided if I'm going to have it on the negative or positive.

Always mount a battery cut off switch on the negative side. Kills the entire electrical system. If mounted on the positive side you still have 12v under the dash even when switched off.

 

[jeepljeff]

I didn't like looking at the big holes in the dash panel so I installed the light covers for them. The gauges rely on outside light to illuminate the faces. There are four slotted windows around the backside of the housings. There are two bulbs with a red glass lens that throws lights out into the gauges as best it can. The bottom can is for the high beam indicator. One giant bulb shines through that little hole in the front. I'm thinking I might use ribbons or some small LED arrays for gauge lights. Early Jeeps have a light on the dash that shines down on the gauges. I need to look at the military light switch to see how I can reuse that switch.

I also got the hi-torque starter installed. It's from a '83-92 Toyota Land Cruiser. I had to drill out and slot the upper holt to 1/2" and I downsized the lower bolt one size. The original starter weighs 25lbs. This one is a fraction of that. I also got the PowerMaster 100a Delco installed. I used a WillysWorks bracket kit. I'm going to have to modify it later so that I can use dual belts but for now it's okay. I still need to pull the distributor and swap that out for a 12v solid state one I have. At lease with these distributors, it's imposable to be 180* out since the part that connect to the oil pump is offset so it can only go in one way.

 

[jeepljeff]

Always mount a battery cut off switch on the negative side. Kills the entire electrical system. If mounted on the positive side you still have 12v under the dash even when switched off.

Here's a question for those following. Should I run a Group 34 (or 65 battery) on the old regulator tray or run dual 51R's in the stock battery box? I've seen a few M38A1's with the battery on the tray. If I put it on the tray, it would make my battery connections really short but also would make a master switch more of a PITA. If the battery was under the hood then it might make more sense to just run the keyed power and any accessories off the master and not run the ground up and back. Maybe it wouldn't be that big of a deal. I've got a lot of holes to choose from especially if I use the old heater hole which is the square one left of the starter.

 

[jeepljeff]

So, some parts came in! Now I've got to figure out how to mount the battery tray to the frame bracket. I'm probably going to just bolt it down. It maybe 8" of cable to the alternator and the same distance to the starter. What gauge wire should I use to the starter? The alternator will need a #4 or a #2 since it's a 100a alternator. The only downside to this setup is that I have a cut off switch on the dash so the -12v will have to go inside then back to where that red cable is going to which is ground.

Now, here's the thing I've been procrastinating about, the distributor. Do I really need to make sure I'm at TDC #1? Looking at the distributor, the gear is on the oil pump and there's an offset slot that only allows the distributor to go in one way. Then from what I've seen, I point the #1 on the cap to the alternator. Like how it's already indexed. If that's the case then at worse I'm going to be only off by a few degrees. Or else I can rotate the engine to TDC #1 which is kind of a PITA as the markings are barely visible. I think the hole someone drilled is off and that rib just above it is the actual location. I'm guessing the same person also penned in the mark on the timing cover. It's almost impossible to see and only really showed up in photos. I guess they didn't want the Russians to be able to time the engine.

Looks pretty good under the distributor cap. It should as it's watertight.

Also, here's what the door looks like for an M38A1. I'm selling them since I don't think I'm ever going to have door on this Jeep. The interesting thing is that the door frames come apart with two slip joints and the whole thing folds in on itself. This is great since I'm selling the doors.

 

[Howard Eisenhauer]

I'm also thinking about removing the vacuum booster that's cobbled into the Jeep. I'm not even sure if it works. I'll have to see how it's installed but if it's easy to remove I'll probably remove it. It's ugly and takes up a lot of room. Thoughts on that?

That's a Bendix Hydrovac. They were used back in the day to improve the braking- from all reports they did that very well. Unless you're upgrading the brakes I'd give it an overhaul & put it back.

 

[jeepljeff]

That's a Bendix Hydrovac. They were used back in the day to improve the braking- from all reports they did that very well. Unless you're upgrading the brakes I'd give it an overhaul & put it back.

Well, now I know what it's called! Think it's better to run that then say a 11" conversion on the single master? I'm not totally against using it. It was just in the way and needed cleaning. The reservoir for it is pretty janky. Looks like a PVC pipe.