1952 M38a1 Build: Not For The Purists

Drove with a T90 and then bought a T90C from herm to swap in my M38A1 with the f134 because it was simple for the lower first and second gears, and desire to share the jeep with first time drivers.

The lower gearing is noticably better for off pavement blm/usfs gravel roads in high range. But different lower 2nd gear is a challenge for extended on-road. The lower T90c 2nd gear means higher reving to get and maintain 3rd gear at an adequate rpm here at elevation (4,200+) and driving curvy roads and hills.... here in the high desert/cascades; the rpm gap between 2nd and 3rd is fun and then not so fun for first time drivers... reving super high in 2nd to shift to get to a rpm range in 3rd to maintain speed...but not for long if there's an uphill. I think an overdrive for splitting the 2nd/3rd gap would solve the rpm issue. 2nd/3rd gap is fine in town. I think either t90 or t90c is perfect if it gets the jeep road worthy.

 

An M38A1 had, a lot of parts had red paint. Probably parts of a donor vehicle that had been used by a fire dept. Dash parts had red paint

Dave

 

Yeah, I'm still thinking if I even need lower gears. I don't plan on wheeling the Jeep too hard though I'm sure the Rubicon would be considered hard. I've driven my YJ over it with 4.10s and 2.72:1 and 33's and it was way undergeared. Had to use too much throttle and with it being over 3000 lbs, you end up crashing into thing. The A1 is a lot lighter and should float over rocks better. From what I've been reading through, a 1-1/8" transfer case isn't the best choice. I have a two 1-1/8 " and one 1-1/4". It's a small bore though. I also want to do an overdrive which complicates things even more. Wish there was a 4:1 over the 3.15. I know there is a 5:1 but that involves a lot more fabrication. Seems like it would be easier to just to T98 and leave the transfer case with just an OD. Maybe I'll come to my senses and just leave it alone and just to the overdrive.

The Jeep was painted with red oxide primer in '58. Seems the Depots were painting them before selling. The '53 donor was also red primered. My A1 was purchased from Surplus directly by an Army Vet. It never went into service with any municipality.

 

With a 4cyl you want 5.38s and t-90j or 4.27 with t-90c they are the same final drive ratio.
Then you want an overdrive with the tera low set.
the t-98 is gonna give a lower 2nd gear than the t90a plus the granny gear.
Play around with this sheet but remember you flat out run out of steam at the same top speed with the f-134 so pick a reasonable top speed and rpm.
https://fireball-v6.github.io/Code/

Tera low 3.15:1
Jack O'Brian Rockeater 4:1
Jeff's 5:1 gears
Kluge-v but overdrive wouldn't be an option.
https://homersgarage.wordpress.com/...ations-or-how-to-make-60-year-old-stuff-rock/

 

So, I guess without having to rehash everything, a AA 3.15 and a Warn OD would be the best setup. For onroad the T90a seems to be pretty good as is. I still haven't driven the Jeep above 30 mph yet.

I've still got a bunch of smaller stuff to deal with in the meantime though. I have no rear lights. Anyone know if a grommet 4.5" trailer light will work with the 5" bole in the body? I'm wanting to run LED's in the back and will probably make both rear tail lights work rather than just have one. Rugged Ridge/Omix-Ada has a bolt-on LED but I don't really want to spend the $140 for them if I can get readily available grommet style lights. I've seen the flange ones used but I don't want to drill anymore holes into the body.

 

Mine has 61K on the odometer. I know the engine was replaced at the Depot presumably in '58 as it had a W13 instead of a W11. I'm not sure if that mileage is correct. The engine seems to be running like a sewing machine and there's no signs of any issues. The Jeep was used as a hunting rig by it's first owner. I can't see putting that many miles on it hunting though. Maybe it was towed? The Jeep did have a PTO winch and a Warn OD on it early on.

 

Well, I went with the 4" grommet lights because they are utilitarian and cheap. Not to mention are bright. Wired it all from spools of wire and used some Deutsch Connectors which is probably overkill but I wanted it to look clean. I had one issue with the holes in the body though. One side was under 5" and one was over 5". I ended up using some 1/4" vacuum line, splitting it and putting it on the edge of the opening and that seem to have worked. Originally the Jeep only had one tail light but I think since there are two holes, if I get pulled over, I'm going to have a hard time explaining that the other side isn't a taillight. I might eventually wire it to the blackout switch so I can turn them off completely. The other issue is that the rear taillights originally do not have driving lights when the headlights are on. I 'm going to fix that and have the rear driving lights turn on when the headlights are on. The other things is that I've gone ahead and wired both sides seperately in case for some reason I may want turn signals down the road. Doubt it but I might as well wire them. I have a CJ5 style highbeam switch and will just wire them, to that. I think I'm going to put power to the blackout and I want to wire the headlights to the switch so it does something. I'll probably put a Deutsch connector on the back so I can repin or add functionality to the switch when I get more time. I think I'm going to put modern Automater gauges in the dash so I have a legible speedometer with a trip meter. The trip meter will be nice for monitoring fuel range once I get used to driving it. The other nice thing is that each gauge will have its own light. I'll have to convert them over to LED though.

I still need to change out the waterpump and finish wiring the front headlights. I bought Phillips LED headlights since I plan on driving this Jeep at night. I got a Painless Wiring relay harness so I just have to wire it to the hightbeam switch to the blackout and then to power. I'm thinking about putting some fog or spot lights in the driving light locations in the grill. Sometimes people convert them over to turn signals but I'm not bothering. I want something useful and I think some fog lights or spots would be pretty stealthy so I won't have to add high Aux lights on the bumper. That's it so far. I've still got to replace the water pump and maybe remove the brake booster. I'm not really looking forward to either though. Working with old bolts and fittings is just asking for something to break.

 

I got to do some welding again and this time it was flux. Never tried flux before. The machine was a Lincoln 211 which is a pretty new welder. I had to fix the machine before I got to use it and sorta slapped some setting on. I used the Synergic or whatever Lincoln calls it and was running a bit hot. Turned it down and it was welding pretty nice. I welded a 3/16" license plate bracket to the backside of the gas can holder so no one will freak out over it having extra holes. I don't plan on running the rear bumpers so there's plenty of room for the plate.



I bought a case of this Rustoleum Forest Green paint. I thought Forest green would be darker than OD but it's not. Looks the same which is to say it's a little lighter than I wanted it. Not a big deal. I'll still use it. There's 2-3 different greens on the Jeep so once it wears in it won't stand out at all. Now that plate high enough that it's not going to get bent up offroad.



Got around to cutting the connector off for the blackout/headlight switch. Was able to get it apart with some Internet help and rewired it. I'm only using a few circuits off the harness so I put a Deutch connector on the other end so I wouldn't have to mess with the connector again. Basically, I'm wiring the headlights and the dash lights to the switch. I can't really put any Aux lights on the switch since they would turn off when the headlights are on since they would be connected to the blackout light circuit. I want to eventually put two fog or spots in where the front blackouts/driving lights go and put a 4" spot where the blackout would normally go on the fender.



Bought a new tool. Gearwrench's Tap & Die set. There's a lot of threads that need to be cleaned.



Instead of getting seal beams or H4's I went with Phillips 6024LEDs. They are a lot cheaper than the Holley's and seem a lot brighter than H4's. The bar in the middle takes a little getting used to. Wish they hid it better though it sorta mimics the blackout. Basically, when the low beams are on the top section lights up. When high beams are on all sectors are lit.




Here's the last major repair for the Jeep. I've known it was an issue back then it was at the High School. When I rotated the crank it spewed coolant. Once I got it driving, it would dump the coolant all over the driveway when parked. I was sort of dreading having to try to loosen 72 year old bolts but they came out easily. They were only hand torqued, it seemed. Got a replacement pump from Kaiser Willys. I believe it's an Omix-Ada M38A1 pump. The main difference is the dual pulley.



Was trying to figure out how to get enough room to pull the pump with the least amount of work. Tried taking the shroud off but some of those screws were tight. Ended up dropping the grill and pulling the radiator which was pretty easy. Only '52 and 53's have a hinged front grill. This also made it easy to flush the block and radiator out. There was a lot of crud on top of the thermostat when I first cleaned it a month ago when I replaced all of the hoses. I only found one big flake. One of the POs did at least put antifreeze in the system so there wasn't much rust. I'm sure most of it was from the thermostat housing as it's a high point and when the coolant leaked down was probably left exposed to some air. Cleaned it up the best I could and painted it. You can see the pits in the metal still though.




I guess I fixed the leaking water pump too good. Seems I moved the oil inlet hose too much and it sprung a leak. So that's another thing I need to do.



Since I had the seat brackets in a container of rusty parts, I decided to san blast them and repaint. I'm just using cheap Rostellum Forest Green which doesn't really match any of the other greens right now. I'm sure it will blend in a lot better once it ages some. I need to dig out all of the salvaged footmen loops and see if I can install those as well. I think I need 11 of them to fill all of the holes.



Yet another problem. I bought a 12v fuel sender a few months ago and I'm now getting ready to address gauges. So I needed to make sure what ohms I needed for the fuel gauge. The sender was supposed to be a 73-10 but I was getting 128-2. I've got to contact Kaiser Willys, the place I got it from and see what they say. I think it's an Omix-Ada part and is supposed to be 73-10. The problem is if I put a 73-10 gauge, I'm going to be at 65 ohms at half a tank which is close to empty on the gauge. I'm probably going to replace all of the old gauges with AutoMeter Z-Series gauges. They're pricey but I want nice gauges and for them to be illuminated. The factory M-Series gauges have two bulbs in the panel that light up all 5 gauges with indirect light. I plan on driving at night so I'd like to be able to see them. So far, I've maybe put 30-40 miles on it with a bunch of short drives.

 

Were there a plug in direct swap light? I've currently got he's but would like brighter

 

Are you aware the the military used several distinctly different shades and finishes of "olive drab?" They are available.

 

6024 = H4 so they use the exact same plug. I'm running a Painless Wiring relay harness so the lights are also getting the full 12v. I did have to unpin the connector to pass the plastic part though the hole. It wouldn't otherwise fit.

Yes. The Jeep was originally painted 34087. Then later with 2430. Then there's a third shade as well. I didn't want to spend too much on paint. I got a case for the same price as 2 cans of 2430. I'm just looking for close enough and mainly it's just there for rust protection.

 

Looked at a CJ5 gas tank and my M38A1 has to be 1-2" taller even without the extra slump. I'm really starting to think the fuel sender is going to be like a little kid sitting in an adult chair with their legs dangling. It's supposedly one for a CJ2/3 but said to work with a M38A1... I might consider installing a Holley LIDAR if I can't get this one to work. Another good reason for getting a speedometer with a trip meter on it.




Went to the local Car's & Coffee and hung out with a few friends. Funny thing is my Jeep was the oldest one there. My friend hadn't ever seen the Jeep running and he owned it 7 years prior and probably had it for 5 years. We're guessing it hasn't been roadworthy since the '80s. I got it in March and had it rolling by May and it was running my July.




Afterwards we got to play around on this hillside. First time ever putting it in 4low and having to lock the hubs. Everything worked though! I was also thinking about doing a T90c and an AA 3.15:1 gear set but after driving it, I might not bother. This isn't going to be a hardcore rockcrawler. I just creeped around in 1st and that was somewhat too low. I know it's not the Rubicon but it did feel solid with the 5.38's and 650-16s. The grass was slick too. I need to get more seat time with the Jeep to really get a feel for what it needs if anything though. I don't really want to put Lock-Rights in it. It's weird wheeling it without seatbelts. I always feel like I'm gonna fall out.

I also found out what some of the thumping noises I was hearing onroad. Turned out the hoods brackets were set really far apart which allowed the hood to slide on the hinges and bang into the cowl mount. Got 4 of the 6 bolts out. The other two snapped right off. Ended up drilling them out and got one to just come out. The other one fought be till the end. I ended up drilling host of it out then tapping the hole again. Good thing I bought a tap & die set just for this.

 

So, this happened today. Was on my way to the local Cars & Coffee and the clutch went out a block away. Threw it into gear and drove it the rest of the way there. Broke the 90* bend right off the linkage. Not even at the slot. Looked like it's been cracked for a while though. Anyone built a new rod from clevis forks and all-thread? I'm guessing 3/8" Clevis? I'll eventually be rebuilding the whole linkage, I think.

 

That looks like it would work well, I know similar has been done before, but in my mind they used heim joints.

 

The bottom rod in the pic is what broke on your jeep (I think) which is stock. The top rod is one that I fabbed with a fixed (welded) clevis one end.

I put the welded end on the peddle side towards the front. The adjustable side is very easy to reach as opposed to the harder to reach clutch cable from beneath. The cable adjustment just looks easy to reach from beneath because the skid plate hadn't been installed yet.

 

Are there any DIY pages using mini heims? I think the main reason I didn't look at heims was cost. Clevis forks are has as much.

 

Ah, nice. I've seen it done on a few Jeeps but never built one myself. What size are the clevis forks? Also, is that rod all thread or did you happen to find a rod that has a solid section that worked?

 

5/16" NF.... https://www.armyjeepparts.com/p-1445-yoke-clevis-516-24nf-clutch-nos-jeep-wo-632177.aspx That was a rod that I had sitting around (because I don't throw stuff like that away anymore) threaded it with a die. I suppose you could us a threaded rod, why not.

 

Maybe this will be helpful?
http://www.earlycj5.com/xf_cj5/index.php?threads/135126/

 

That's good to know. At least I know it's 5/16". I'm sure I can find those clevis at any hardware store. Though $10 isn't bad for the clevis fork, pin and clip.

I've got this old one off a 2A that's unusable. The one above it is my broken one. It had a groove cut into it and it didn't break at the groove but at the 90*. Looked like it's been broken for a long time with all that rust. Then it broke off.