I just bought an M38A1

[clinto]

I want to get some good rubber floor mats for my M38a1, does anyone know what fits? Maybe CJ5 mats?
Also, if I install a PTO winch, but the extremely expensive Original 50s Ramsey one, does anyone know the limitations?
And why the recommendation that I install locking hubs? Every CJ I've had already had them. What does the M38A1 have?

CJ5 is probably close enough.

I don't know the limitations, but it's probably waaay more than sufficient for the vehicle, especially when run through a snatch block. I've never seen a factory winch on an MV that was insufficient.

The M38A1 will have "drive flanges" like a deuce. There is no freewheeling with them. So when you are in 2WD, the front axles, gears and driveshaft are all turning.

Oh, and one more question. I want to install seat belts. What length do I need?

Don't know-early CJ5 is probably again the best best, short of some universal kit.

 

[zout]

Kind of along the same line as what Modified said above and having conversations around the two jeeps in the garage (waiting for engine) there was an interesting point made.

When the military used these and were going and doing everything possible with them - mud/snow/bogs/etc - they had an extensive pm program with an extensive maintenance program for care afterwards of these units.

When the CJ5 came along everyone thought COOL - we can do the same thing - that included taking that ole military jeep out and doing the same thing with it. But civilians were basically clueless to what had to be done to maintain them to tolerate that usage. Go through the water or mud and hit the highways and not look at it twice besides just greasing it.

This does not include the ones that knew what had to be done - it was the rest of the general public that wanted a "JEEP".

Makes you wonder about the bigger units !

To get back to your point- when we were looking at the jeeps when Clinto was there we were discussing the overdrive as well.

 

[Deadguyllc]

I mis-posted. What I actually meant to say, was that I was thinking of installing a PTO winch that was not the Original model. If I do that, what do I need to look out for? And, are the present hubs on the M38a1 kind of like the manual FJ Cruiser? It's AWD, so the front differential is in action when in 2wd, but it actually locks in and works hard when you shift into 4wd. If that's the case, do I really need to slap big ugly manual hubs on the sides of the front wheels?

 

[zout]

Check out some of the 24v winch set ups like Warn. I have one on the 109 - sort of lightweight - but its all I need.

 

[Deadguyllc]

No answers on the hub question? And can I install seat belts without drilling holes into my Jeep?

 

[Deadguyllc]

It has warn locking hubs, so I'm all good there. I was told "don't fall for that overdrive bs. You gain almost nothing because the engine is so small".
Aside from the seat belts, my new question concerns the oil I use for differentials and engine. In my newer trucks, I've always used synthetics. Is it to much for a car this old?

 

[clinto]

It has warn locking hubs, so I'm all good there.

Cool-someone already spent the money for you.

I was told "don't fall for that overdrive bs. You gain almost nothing because the engine is so small".

I would disregard advice from this source in the future.

I am not sure what this even means- "too small" meaning it won't have enough power to "push" the taller gears? That's baloney.

"Too small" meaning it is such a little 4 cylinder that it wont' benefit from lower RPM's or even worse, that you can drive it at highway speeds without damage? BS. It may have small displacement but it's a looong stroke engine. Extremely high piston speeds.

Again, ignore this person in the future.

Aside from the seat belts

I am still not sure on how to add seat belts to your vehicle in a way that would

A. look original
B. require no drilling

I just dont' have any experience.

my new question concerns the oil I use for differentials and engine. In my newer trucks, I've always used synthetics. Is it to much for a car this old?

I would run straight Napa GL1 90wt gear lube in the axles and transmissions. I can't remember what the M38A1 LO calls for, but I suspect it's GL1. Order it in 5 gallon buckets under part # 65-205.

In the engine, I'd run something like a 10W-30 detergent blend oil. Nothing fancy.

I don't know if synthetics would be "too much" but I'll guess they'd leak more, especially on old gaskets and seals.

 

[jamesfrom180]

I've always wondered about the detergent blend foaming alittle in that block. Alot of splashing going on in the case. Any thoughts?

As for OD being BS, that person does not understand basic gearing. I'll take a 10 hp engine to 80 mph with a >12 gear box. Now it may be more practicle to drop a bigger engine in, but you are talking about a specialty application that you probably don't want to do that in.

We need some more pics of your ride

 

[mutt1966]

I cant agree more with Clinto overdrives are one of the first things I would do for it, having that half gear between 2nd & 3rd on a hill just the thing ya need not to mention being able to cruise at a reasonable speed without winding up the engine, the down side is the lack of emergency brake that is sacraficied because of the Overdrive can be remedied with some aircraft cable

 

[Deadguyllc]

The advice came from the guy who built up the Jeep. He says, with the 4 cylinder, it doesn't add much, is expensive, and essentially a waste. He also says he can ride it comfortably at 50 MPH.

 

[tigger]

I have the seatbelts out of a ford ltd rear seat in my jeep they work well. had to drill and reiforce where mounted. I have seen them bolted to the seat but i dont think that is a good idea! Go to the junk yard got seat belts for $10 for mine

 

[quickfarms]

The overdrive serves two purposes.

First is is an overdrive to slow the engine rpm down when you are running above 5o mph. It is true that the engine does not have a lot of hp and you will have to down shift and gravity will slow you down on the hills but when the freeway is flat you can cruise at 60. I have found that over 60 there is a front end shimmy caused by the ND tires.

The second purpose of the overdirve is to split gears. You now have a 6 speed transmission. To me that is as much an advantage as the speed. In parades I run in 4 lo first gear and some times first od. On our convoys it is not uncommon for me to split gears and run in second od.

The parson that says the engine does not have the hp to use the od does not understand how to drive the jeep.

If you have a series of rolling hills on the freeway I will sling shot my self down the hill to get up the next hill faster.

One word of advise is that if you want to take a jeep on the freeway and have a white knuckle time make sure everthing under the jeep is in perfect shape. Do not just grease it, go through the everything and make sure it is to factory spec.

My list of required mods on a jeep include.

Seatbelts, I used the generick black ones from aurtozone (I think you will have to drill some holes for the front ones but the rear ones can be attached to the lower bolds for the jerry can holder and spare tire, not the perfect alignment but you do not have to drill holes)

dual brake lights with Gamma Goat Lenses

overdrive

Good luck and let me know if you want pictures of my seatbelts

 

[quickfarms]

I looked at my front seat belts and it does appear that I drilled holes for the front seat belts

one end of the seatbelt is mounted to the front of the wheel well and the other end is mounted to the floor just ahead of the gun pedistal mount.

 

[Deadguyllc]

Installed seat belts. Ordered spacers so I can do a front disc brake conversion. I am replacing the T90 with a T18 transmission, will I still need an overdrive? Do I need just the Gamma Goat lenses? And to wire my right side tail light so it comes on with my left side one? And finally, the big question, how much of a pain in the ass is it going to be to install turn signals?

 

[quickfarms]

In an earlier post you indicated that you wanted to install the seatbelts without drilling holes but now you are going to perform major modifications.

Why are you adding the disc brakes?

The drums work fine unless you like to take the jeep swimming.

Another option to the disc brakes is 11" drum brakes. With these you will think that you have power brakes and never have to mash the brake pedal.

Why are you changing the transmission?

The t90 is a great trans for the four cylinder or even a v-6. It has a 1:1 third gear.

The t-18 is stronger if you are running a v-8 but you will only gain the granny first. This is great is you are rock crawling but you can get similar reduction using the transfer cases lo range. Additionally the high gear of the t-18 is still 1:1 so you will still need the overdrive.

Tail Lights
In addition to the gamm goat lenses you may need a second diverside light if your passenger side lite does not have the brake light bulb. Look at the back of the light and count the number of wires. if the passenger side lite has less wires you do not have a brake lite bulb in it. another option that I have sued on trailers is to install the gamma goat lenses and change the bulbs and wiring so that the bo lights are now the marker lights and the bottom bulbs are stop lights. this is an option due to the fact that the bo lights do not work with the gamma goat lenses.

Turn signals
I considered this but I believe that it would involve major surgery to the wiring harness and I think it would be a pain in the ass to install but I would like to hear from someone that has done it.

 

[Deadguyllc]

I can add disc brakes without any drilling or cutting. The current drums have no stopping power, and even if I go up from 9 to 11, I still doubt it will be nearly as much as the disk brakes. The tranny is worn out. I could either put in another T90, or upgrade to a T18. The T18 being virtually indestructible, I went with that. I switched a T18 for a T90 in my CJ7, and it shifted way better. It is from the same era, so it's not too much of a change, and there is no drilling or fabrication needed. I will still get an overdrive. The steering linkage is completely shot as well, and rather than just replace the parts that are there, I will install a HermtheOverdriveGuy better manual steering kit. I will need to wire up the other tail light.
I installed seat belts, and did have to drill holes, but I tried to hide them under the seats as much as possible.

 

[truck1]

Don't do it!

I've got a '44 GPW all rebuilt original by me,and it's 45-50 max for that rig.You will ruin it and have white knuckles @ 65!The design is not meant for modern freeway speeds.I've tried it before and it is a ball buster.I run my jeep easy and enjoy the smell of canvas and the cool factor.Don't get me wrong I,ve wheeled it pretty hard hunting and retrieving game but It is what it is an almost 70 year old war design meant to last a couple years @ best.From your pics you got a nice original rig .Enjoy it for what it is.

 

[Deadguyllc]

Don't get me wrong, I don't want to fly up and down the highway. I'll mostly do 30-40. I just want to go 55 on the highway without overworking the engine when I go out of town to things like camping sites. At 20MPH, I have to stomp down hard on the brakes. I won't add a vacuum assist, or bigger tires, just better brakes up front. The T90 doesn't sync well between 1st and second, and my old one had worn sycros and was 59 years old!
I'm putting new, but true to the original shocks, rims, and tires on it. The steering is shot, and if I just rebuilt the old one, it would have problems before too long again. The frame, motor, gauges, canvas top, all that, will remain the same.

 

[Deadguyllc]

I found someone selling original, unused M38A1 steering boxes! I'm trying to keep my Jeep as true to the original as possible. The only serious changes from the original I have now is putting in a T18 tranny, and front disc brakes. The T18 is a much better tranny, all the main gears are synchronized, and they started making it in 1955. I don't think it is too far of as far as keeping the Jeep original. I installed seat belts, and I have gamma goat lenses on the way. I assume I'll need to splice the right rear brake light into the left one.
The engine is brand new, as are most of the parts attached to it, but keeps dying if left on for longer than 20 minutes. The fuel line runs right between the exhaust header and the engine block, and I've ordered some black heat shield tubing from Summit Racing to cover it.
I am debating the overdrive, as I hear it burns up engines. The problem with an overdrive, is I keep hearing so many different opinions, I'm not sure what to follow. I hear it's great. Then I hear it doesn't do much. Now I hear it wears out the engines quicker., but that was from a guy that had the Buick Dauntless 6 cylinder in his military jeep. Opinions?

 

[BillF]

An overdrive will prevent wear on your engine. It keeps the rpms down so the engine is working less. The t90 is also a very good transmission. the only problem with it is you cant down shift from 2nd to 1st without double clutching, but 1st is so low you wont need to shift it to it will already moving anyways. Putting in the t-18 will lower the value of the jeep.

The cj2a page has a good discussion on overdrives CJ2A overdrive - The CJ2A Page Forums - Page 2