1952 M38a1 Build: Not For The Purists

Getting some working gauges installed. Splurged and got some AutoMeter gauges instead of the repop. The original gauges have slots/windows on the backside of the bezel that allow light in. There are two lights that are seperate from the gauges that bleed light to the gauges. I wanted to drive the Jeep at night and didn't think the indirect light was going to cut it. The AutoMeters are all self-illuminated. I'll need to replace the T3 Wedge bulbs for LEDs though. I did have to open up the speedometer opening a few mils to get the gauge to fit. The other gauges just dropped right in. It's tough finding a speedometer that isn't 120 mph or higher.




They're nowhere near as bright as in the pic. I'm hoping once I switch out the bulbs for LED's they will be brighter than they are though. They have more of an dark orange glow.




I'm going to eventually replace the two dash light housings and put a USB charger port in one. The other side I put use a accessory port so I can plug in my fridge and hiide that in the back. I've also got to figure out what I'm going to fo about the fuel sender. I bought one that was for a CJ2/3a that said it would work for an M38A1. Under closer inspection, it fits but the military tank is 7 gallons larger. The tank sits 1-2" taller than the CJ5 tank so the float doesn't even get close to the bottom. The other problem are the ohms. I was under the impression that the sender would be 73-10 ohms. Well it turned out it was 130-0. I bought another one from another reseller that stated it was 73-10 and it too was 130-0. So, now, I'm thinking I'll get the Holley LIDAR fuel sender and make it work. Worst case, I drill a new hole in my brand new gas tank. I think it will fit in the same hole as the OE sender though. Didn't really want more electrical stuff but I also want a working gas gauge.





Unlike the CJ's of the time, the M38A1 used an electrical temp and oil pressure gauge so keeping with that theme, they stayed electrical. The coil is actually where the original oil pressure sender usually sits on an M38A1 but is where the coil sits on an CJ. I could have put the oil sender on the block and removed the line but it's down low and isn't very accessible so I figure I'd leave it for now. Makes running wires really easy though as they're all together.



Also, after that off-roading escapade, the next dat the clutch linkage broke. The original linkage is a metal rod with the ends bent over 90*. Typically what happens is that the rod or the bracket that attaches to it gets grooved and will eventually break. Mine seems to have been broken for a while and the offroad adventure just finished it off. I decided to built a new one out of hardware store parts even though it's more expensive than the repop part. At least now I can rebuild it in the field. I keep a spare in the Jeep.

 

Those gauges are cool.
Never had luck with the M38A1 original gas gauges, just carry a stick to check the fuel level. The needles swing a lot when driving.
Those look good on the original dash.
I like the mods with a nod to the military history.

Dave

 

It's hard finding gauges that are simple and clean. Not to mention aren't 120 MPH or more. I'm sorta determined to get the fuel gauge working. Having a trip meter will help though. The filler neck is huge on an M38A1 so I can see into the tank easily. I've sorta got it figured out how much gas is at what level.

Yeah, I kinda wish they were green. I might paint them, I might not. I do wish the bezels didn't stick out as far as they do but that's pretty minor.

 

Had a slight setback. Went to fiddle around with the Jeep and the battery was really low for some reason. It was fine when I put the gauges in a few days ago. I don't think I left anything on as only the gauges were new to the circuit. I haven't had any issues with the headlights draining and I didn't leave the ignition on either. We did have out first few cold days which is what I think did something. I put the modern charger on and it wouldn't charge more than 7v before shutting off. Talked to a few friends and they recommended jumping it with a good battery to sort of brute force charge it. It's somewhat common to have to do that to Optimas for some reason. I've never had issues with them ever though. So, instead of jumping it I pulled out the old school charger and that seems to have done it. It pegged the meter then it fixed it within an hour or so. Swapped chargers and it clicked over to maint 13.2v after a full charge which is what it's supposed to be.

Turns out, I had been putting the headlight switch into Park mode which turns off the headlights and the dash lights. Or so I thought. What it does it turns off the headlights and set the dash lights to dim. So I was leaving the dash lights on even though I couldn't really see them lit up. The dim is set up for 24v so they're very dim when you run 12v through them. Glad I figured that out though.




While the battery was out I took the time to take the Barnes4x4 battery tray out and finish painting it. I just quickly painted the underside when I threw it in but it was raw metal and was starting to look kinda grungy. I made sure to paint it with non-correct OD Green from Rustoleum so the Military Vehicle guy's can complain about something else.




Put the battery back in and fired up the engine. Oh and look 30 psi of oil pressure! Also 14V from the alternator. So currently 4 out of the 5 gauges work Or so I thought. Strike that, the speedometer isn't working. I think the square drive is too short so it's not spinning the gauge. Maybe push the cable forward from the transfer case? The drive wire is pretty far back inside the sleeve. I'm not sure if that's how it's supposed to be from the factory or not. Will need to check that out. I'll get the gas gauge working once I order the expensive sender for it. It's really not that expensive when an M38A1 sender is around $125 already. But I've also got two $40 CJ2/3 senders that are useless to me right now.



I want to eventually remove the two domes which are the housings for the OE dash lights and replace them with USB port and a accessory port kinda like this. This is the dash from another M38A1 owner @myjeepexperiance



Getting it ready for the impending storms. Supposed to rain for at least a week.

 

Dash is impressive! As much as I like the original Jeeps, your mods look very useful with a nod to the Jeeps military history. Always wanted one more A1 modified to be more useful off road. My 64 M38A1 had Lock Rites front and rear and it takes a football field to turn it around. May put locking hubs on the front to lessen the turning radius when not in 4-wheel drive, but I still enjoy driving it.


Dave

 

Yeah, I want this Jeep to remain looking original but not be. I'm thinking about going with Lock-Rights front and rear but haven't gotten that far. I'm also thinking about gearing. I'm wondering if I want to do a T98 or maybe a 5:1 in the Tcase. I've been told by Seth Hensler that the 5:1 might be easier even though it involves a lot of cutting and welding to the case. 3.15 doesn't really seem worth it for the price. I know Sam Fuller and some others have T90c/3.15s but I kinda like the gear spread of the T90a. The T98 would be similar to the the T90c but with the granny first though. I also want to run a Overdrive so that might also dictate which route I go. I haven't even looked to see what 5:1s cost. I think Jeff Petrovich is the one who makes them.

But really next up is to finish the gauges and then onto brakes. I want to get rid of the Bendix HydroVac and swap the 9" drums for 11"s.

 

What are you wanting to do with the Jeep?
I would avoid the 5:1 custom gears and the hassle that goes with them.
The Terra Low gear set is a proven platform that requires little modification but has big payoff.
If your jeep has 5.38 axle gears and you put T90C gears (3.34 1st) in your transmission, you will be at 56.6:1 crawl ratio with Terra Low gears in the transfer case.
That coupled with your small tire size will be a combination that will do anything within the limitations of your suspension and tire diameter.

 

I plan to drive it to and from trails while being able to do some Rock Crawling. I currently like the T90a gearing for on road though. For offroad, it's not bad really but I could see breaking some stuff trying to bump it instead of crawling. I'm thinking about putting Lock-Rights in both axles even though I want to drive it on backroads.

I've heard the simplest way would be to do the 5:1 even though it requires some cutting and welding. T98 would require new driveshafts and maybe some cutting of the shifter opening. T90c and 3.15's would require rebuilding both. Not sure which would be the best for me though. I also want to run an overdrive. That might go in before doing any gear changing. Maybe just doing the 3.15 and OD would be fine. Not sure of the T90C would be much of a difference offroad. On road the gap between 2nd and 3rd might get annoying. I guess with an OD, I could split the gears and get the best of both. Will have to think about it. Are there any other lower gears other than AA and Petrovich? I know there were JeepEater/RockEater gears for a while.

I've got a spare T90 which has the 11" input shaft. I think it's for an I6. Not sure of the gearing with the matching D18. It's a 1-1/4" shaft as well. No parking brake so I guess '70 or later? I also have the original T90a from the A1 that's basically just the case. I also have all new (KaiserWillys.com) internals but I haven't put it together yet. I'd need a new input shaft and cluster gear, to convert it to a "C". I have a D18 case from the A1 as well but it's a 1-1/8".