51 M38

[jake138]

Jake,
Loving your posts on your restoration. Tons of detail and photos! I don't have the mechanical background most of the others and you do but I can appreciate all the work and ingenuity there.

On braking - I've had my 1952 M38 since 2008. Braking, as you pointed out, is different on that than a modern car and that's the biggest difference and thing to remember when driving it.

I mostly drive my jeeps out on Martha's Vineyard. Lots of sandy dirty roads, sandy/dusty paved roads, and mostly speeds below 35-40 mph on the roads. The biggest challenge I've faced isn't being able to brake or slow down quickly it's dealing with the other drivers. Most of them are clueless - like most people (another conversation for another time). Modern vehicle drivers have little appreciation for how physics works and have too many distractions (at least that's the way it appears to me). They're often oblivious to motorcycle riders which is kind of where I put myself as it's a non-standard looking/acting vehicle. Some of the drivers are great though and do give me plenty of room, wave, and appreciate the older jeep.

However, aside from drivers the biggest challenge are the hordes of bicyclist's and moped riders. They're by far the worst (and the people that blindly walk into the street or across intersections and crosswalks).

So, aside from my rant on tourists in tourist spots doing tourist things I think the biggest challenge you'll likely face are those that are blind to their own surroundings and present a challenge to any driver. The brakes have always worked well for my in emergencies. I just do my best to identify my risk vectors as early as possible from our surroundings. The jeep does just fine otherwise.

Josh

Josh,

Thanks for the kind words, I'm glad to hear that people enjoy the pictures and explanations. I learn by doing, and this project has been quite the learning process for me, so I hope to document what I learn for any future mechanics.

I have to say that after having motorcycles on and off from the time I was 17, the distractions that other drivers succomb to are the sole reason I retired my riding jacket a few years ago. No matter how safely you ride, there's always a chance that someone else on the road is trying to send a text, or watch Netflix, or do god knows what else, and it's all over. I still have my helmet, but I stick to the woods when I want to go riding now. At least I know the odds of a tree jumping out in front of me are much less likely than an SUV .

I have yet to ever make it out to Martha's Vineyard, however once this pandemic nonsense starts to wrap up, it still remains high on my list of places to visit. I'm from central Connecticut so it would only be a few hour ride to the ferry for me. We'll start scheduling some MC jamboree's once the world returns back to normal .

Yes, great detail and how to.
I have some over sized drums that were turned too much and every shop I talked to said they don't do that anymore so I had to go with some later military replacement NOS drums that don't have the slit to check the brake shoe adjustment.

For a few weeks, I greatly considered cutting the slit in my drums myself, just for the sake of trying to adjust them with the shims per the TM. I still might actually end up trying to cut the slits with my drums later, as everything I have assembled on my brakes will be coming apart again some day after running-in the shoes.

I still have my old drums in the shop to practice cutting the slits, so I might just tinker around with them if I have some spare time . If I develop a successful method for accurately cutting them, I will let you know.

~Jake

[jake138]

I've been bouncing around, changing my project based on my mood. There's plenty to do, so when I feel like painting, I paint:


Front section, about a day dry. Low gloss black enamel, lays out really well. Feels pretty resilient to damage, yet still slightly pliable and hopefully won't crack. Brushed all the areas I can reach, will spray the rest.

I installed a replacement rear bumper from Kaiser Willys, and it fit fairly nicely. Of course, replacing the rear bumper meant cutting off the plate for the pintle hook and welding it back onto the new bumper. So after a few passes with the Handy Mig, I was satisfied with the repair:


The more obstute observers may have noticed in my older photos that the rear bumper has been installed and primed for quite some time: I installed the bumper quite a while ago and just never got around to welding it back on.


This was two passes with the Handy Mig, using a MAP gas torch to add some extra heat to the thicker plate. If you are using flux core wire, you need to know if you have multi-pass or single-pass wire. This will make your welds all that much better.


Primed again after cooling.

After the primer was dry came the top coat for the rear frame section:


Now at this point, I didn't feel like painting much more. So once the paint dried, I started working on brake lines. I'm using Nickel-copper brake line and bending/flaring everything by hand. I have always wanted to experiment with ni-cop brake lines, so the Jeep was the perfect vehicle to "play".


First brake line on the rear axle. Ni-cop lines bend so nice! Very easy to hand-bend everything just the way you want it.


Ended up making a few clamps to hold the brake line to the axle tubes. I cut some 1cm wide strips of 22? gauge aluminum, contoured it around the axle and brake line, then drilled a small hole for a nut and bolt to clamp it down.

After finishing the rear axle, I moved to the front, starting with those S lines between the wheel cylinders and rubber lines on top of the knuckles. Originally, I had ordered those lines pre-bent and flared from Quadratec, figuring that at $3 each I could save myself some time and hassle. Turns out, I was wrong! Those pre-bent lines were not even close to fitting correctly. Both the top and bottom "legs" of the S were too long and I couldn't even fit the line in the area behind the backing plate. Also, the total height of the S was too tall, so when I threaded one end into the wheel cylinder, the other end was almost 3/4" too high to meet the rubber line. After cutting off both flares, shortening each leg and reflaring both ends, I tried to gently massage the line into place. After a few minutes, I got the line into place, however I had accidentally kinked one of the bends to the point that I would not feel comfortable using it. So I removed the line to compare it to the unaltered pre-bent line that was supposed to go on the other side of the axle:


The bare line is the one that eventually fit, albeit I kinked it and cannot use it. The black line is the other pre-bent line unaltered. It's hard to fully show in a picture how different they are, however I assure you that the differences are substantial.


This picture shows a little better how far off the height was, as well as how the bends simply are not in the right positions.

My final gripe about these lines is that although the flare nuts are a Standard thread size of 3/8-24, the hex itself was made for a Metric wrench! That's just unacceptable for an American Jeep to need a Metric wrench for a brake line! That was the final straw for these pre-bent lines.

I have been practicing bending the ni-cop lines to match the steel one I got to fit, and unfortunately I'm having one helluva time getting the bends that tight without kinking. I will be purchasing a set of "pliers" made for bending brake lines and I will update this post once I have made progress with those S lines.

[wesk]

unfortunately I'm having one helluva time getting the bends that tight without kinking. I will be purchasing a set of "pliers" made for bending brake lines

Have you tried filling the tubing with fine sand first then bending while using a wee bit of heat?

Also the wrap around style tubing supports often help stop the tube flattening.

[Xamon]

Okay sorry but I am gonna nit-pick... that is not the rear bumper, it is the rear crossmember. again sorry but it is those dang nits.. I can't leave them alone

[jake138]

unfortunately I'm having one helluva time getting the bends that tight without kinking. I will be purchasing a set of "pliers" made for bending brake lines

Have you tried filling the tubing with fine sand first then bending while using a wee bit of heat?

Also the wrap around style tubing supports often help stop the tube flattening.

So an HVAC teacher at my school showed me a set of "spring" like tubing supports that wrap around the tubing, however he did not have one that went down to 3/16". I considered purchasing one, however I'm worried that it might be a huge pain in the neck to remove it once the bend is complete.

I had not considered using sand, and now you've piqued my curiosity! That will be my next venture... Thanks Wes.

[whydahdvr]

I have tried using the flexible spring-like tubing to help shape curves on brake lines and other small tubing - but haven't had much success. I also had the same concern, especially on tight curves, of getting the spring tubing off.
Wes's idea I have heard of before, with great success, now that he reminded me of it. Hot sand helps to heat the metal evenly for easier manipulation and provides a limited compaction medium inside the tubing to help with the bends. I don't remember where I've read/heard of it being used - I want to say also in context of the LRDG making field repairs - but I think Wes's suggestion is the one I've heard the best success with. The challenge then is getting the right sized sand/medium and making sure nothing is left behind later.

[RonD2]

I've heard of the sand method used for bending copper tube to make moonshine distillery

I've also heard that there's either 2 different type, size, part numbers for those "S-tubes" where one fits perfectly out of the package and the other is a mess, or that some vendors are selling defective S-tubes. I don't know which or if both is true. I never bothered to research to see if there's a part number difference for S-tubes between all the different jeep models that use them.

[jake138]

I've also heard that there's either 2 different type, size, part numbers for those "S-tubes" where one fits perfectly out of the package and the other is a mess, or that some vendors are selling defective S-tubes. I don't know which or if both is true. I never bothered to research to see if there's a part number difference for S-tubes between all the different jeep models that use them.

I purchased the Crown JA001488 from Quadratec and I can assure anyone who reads this that it did not come close to fitting an M38 right out of the bag. According the Quadratec, this part number fits everything from a '41 MB to a '59 CJ5/3b . They even specifically list it to fit any year M38.

I left a 1 star review on the product page. Hopefully someone else can learn from my struggles.

[jake138]

Taking Wes' suggestion, I started a new pair of S lines by cutting the lines to length and flaring both ends. With both ends flared, I wrapped one end with electrical tape, and using a small bit of paper as a funnel, I filled the line from the opposite end with red craft sand I purchased from Hobby Lobby for $3. I chose red so that the color would stick out clearly when it comes time to wash out the lines.



With each scoop of sand added, I would gently tap the side of the line against the rubber grip of my pliers to settle the sand down and pack in as much as possible. I was able to watch the sand level drop lower into the line with each set of taps, reassuring the fact that I was packing the sand into the line tightly as I went. Once the line was filled, I wrapped the open end with more electrical tape so that I wouldn't spill all over the floor.



After looking at several different pairs of line bending pliers online, there was only one pair that I found that I could purchase locally, which happened to be at Harbor Freight. Reading the reviews for this set of pliers gave me absolutely no hope that these pliers would work right out of the package, as the reviews were honestly some of the worst things I've ever read about a tool that I fully intended on purchasing anyways. For $8, I decided to take a chance with them, knowing that I would need to heavily modify them to get them to function properly.

The largest complaint in the reviews for these pliers were that the jaws did not align correctly, and that they severely kinked the lines when you tried to use them, which I proved is 100% factual, right out of the package. I did not take a picture of the damage that they did to a test piece of brake line that I used, but I did take a picture of the jaws clearly misaligned.



One problem was that the areas in between where the line gets held were not flat to each other when the jaws were closed, so I used a file to cut them flat. Then while holding the pliers closed tight, I used a 3/16" drill bit to clean up the through hole so that both jaws contacted the line evenly.


You can see that I only modified the 3/16" section on top, and the 1/4" section below is still clearly mismatched.

While test fitting the pliers to the line that I had previously bent by hand, I saw that the radius of the jaws would not be small enough to bend each half of the S as tight as necessary. Using the side of the 3/16" drill bit, I gradually shaped one jaw to be a much smaller radius.


You can see on the right jaw where the coating has been removed and the radius is now much smaller than the left jaw.

Now that the jaws were cut evenly, I wanted to make sure that I would not scratch the line while bending. I contemplated using Plasti-dip to coat the jaws, however, what I had floating around the shop instead was liquid electrical tape, which is actually much thinner and easier to replace.


Two coats of liquid electrical tape later, the pliers were ready to bend.

My first attempt, I bent what I would call a 2-dimensional S, and as you can see from the picture, it would lay flat in the palm of my hand.



This did not work. Even though the bends were tight, and when installed the flare nuts did align correctly, the line itself was blocking the bleeder on the wheel cylinder. After studying the S lines I had originally purchased, I decided to take a more 3-dimensional approach on my next attempt.



This extra "twist" allows the line to reach around the bleeder screw, and was actually much easier to bend than the 2-dimensional one. My only suggestion for attempting to bend this is to complete 2/3rds of the top bend, then rotate your pliers 45 degrees to finish that first bend, leading into the middle area that transitions into the bottom bend. During the first third of the bottom bend, start rotating the 45 degrees back, and you end up with this sort of "twist" that doesn't actually require twisting the line, if that makes sense.

I would like to thank everyone for your suggestions! The sand worked perfect, was easy to clean up, and gave great results with no kinks. The pliers I modified gave almost perfect results, with only 2 small scuffs that I can totally live with.

[wesk]

Jake,

Thank you for a lesson very well presented! Glad your S tube fabrication is resolved.

[RonD2]

Hi Jake,
Good stuff! Endeavor to persevere!

Maybe it's just me, but the flare nuts in your photo look like the long style to me, twice as long as a regular flare nut? Any reason for that?

I'm still looking to crack the code on my memory through the various jeep forums about defective or two different types of S-tubes being sold out there....I can't imagine everybody has to do what you just did in order to make a common part. I sure hope not anyway. If true, yours is the 1st post I recall seeing about it. Pioneer!

[wesk]

Inverted flare brake line nuts came in both short and long versions.

As for the issues with new production "S" lines, I have never taken a new one out of the bag and got it threaded on by hand without having to fine tune the bends. Keep in mind the "never" word here covers the last 60 years of of my wrenching.

[jake138]

Maybe it's just me, but the flare nuts in your photo look like the long style to me, twice as long as a regular flare nut? Any reason for that?

As Wes mentioned, there are short and long thread flare nuts. I chose to use all brass flare nuts with the ni-cop lines because I wanted to minimize the number of connections with dissimilar metals. Since brass is an alloy of mostly copper, my hopes are that neither the lines nor the fittings will oxidize to each other and prevent them from coming apart later. While searching for brass flare nuts, I just decided to stick with all long threads instead of buying both lengths. So far, the long threads have fit everywhere I needed them too, and worse case scenario sometime later in life if they still end up getting corroded in place and do not want to be removed willingly, the extra thread length will give the vise grips some more to hold onto .

[jake138]

Hard to believe it's been 7 months since I've actually posted in my own build thread! Since my son was born in May, time spent on the Jeep has been sporadic and not as large of a priority, nevermind taking the time to document progress here. Here's a recap of what I have accomplished since April:

Tore down the transfer case and revealed a lot of internal mud and rust-pitted gears:


Complete tear down of the case


Light media blast


Boring out the intermediate shaft hole to upgrade from 1.125" to 1.25" shaft


Transfer case and transmission came out of a late 40's truck, but the output gear cover definitely had OD green!


Primed


Painted


Scoring on the front output yoke, and the Speedi sleeve I later installed


Pitting on the rear output yoke, also fixed with a Speedi sleeve


Transfer case, all assembled! I did not take any pictures of the rest of the assembly, as I was working for a half hour at a time some nights, focusing more on little time I had to work and not taking pictures. If you've read Rick Stiver's guide, theres not much more for me to photograph than what's already in there.


Starting on the transmission, shift tower off and ready to pressure wash everything


Loads of mud and pitted gears


Poor gears, I drove around my yard for years with it looking like this


Mud everywhere


After pressure washing, turns out there was a transmission under all that mud and grime!


Transmission torn down


Case painted


I've been scouring the internet pretty much since May looking for all the parts I would need for the transmission rebuild. I was finally able to score the last gears that I needed this week. I'm swapping in the cluster gear and input gear from a T90C for the lower 1st and 2nd gear ratios, and it's taken quite a while to find everything NOS, but I finally have everything in hand!

Input shaft, sliding 1st/reverse, reverse idler, and reverse idler shaft, all NOS


Haven't taken a picture of the cluster gear yet, but I probably will take a final picture of everything before it all goes back into the transmission. I ordered the master rebuild kit from Novak, just waiting for that to come in.

In between tearing down the transmission and looking for parts, I was able to bolt up the master cylinder. I upgraded to a Wilwood dual cylinder so that I wouldn't have to worry about losing all brakes if one line leaked. I made a bracket out of some high carbon 1/4" thick structural steel to bolt up to the same holes inside the frame as the original side-mount master cylinder.




New firewall mount-style master cylinder installed to bracket




And that's it, 7 months of progress all in one post! Slow going is still going though, I suppose!

[jake138]

Made some more progress the last few months:

Transmission rebuild is done. Went with the lower gears for a T90c and was only able to reuse my case and shift levers, everything else was replaced with NOS parts except the main shaft and second gear are reproduction.


Mated the transmission to the transfer case at the shop because I needed to make the spacer that goes at the end of the main shaft to set the correct end-play. I thought I had taken pictures of indicating the end-play but I couldn't find them on my phone.

Brought the transfercase/transmission and engine home:


Finishing up the new shackles and bushings, I realized that the driver side front shackle was vertical, while the passenger side was far from vertical:




Probably has something to do with these homemade spring mounts that Bubba added a long time ago with the driver side sitting an inch further back:


Decided to bolt on the new correct passenger side mount, then do some light beads to help hold it down. Since I couldn't get into the inside of the frame boxing on the driver side to hold a nut, the old mounts were just welded, so I decided to just weld the new driver side mount. Used the hi-lift to gently persuade the front axle to be aligned, it was only off about a half-inch but I couldn't hold it in place with one hand while welding with the other.


Wanted to use shorter grease fittings for the shackles so I made some aluminum adapters that slide through the inside of the bushing and have a flange that holds them, similar to what I believe the military issued after they found high pressure grease guns would blow the threads right out of the bushings.

Recessed grease fitting, adapter withouth a fitting, adapter with fitting, compared to a standard zerk fitting:


Three of the four zerk fittings on my original shackle bushings had the threads ripped clean out, which is what gave birth to my idea of aluminum bushings that won't destroy the threads on the bushing if they get hit by anything in the woods.

Protusion comparison between standard zerk and my aluminum adapter with recessed fitting.


Found a good used Superwinch X6 24 volt winch on Craigslist. Tested it quickly with 12 volts just to make sure everything worked.


Now that I have a winch, I want to make a winch plate that would double as a skid plate and protect anything like tree branches from coming up behind the bumper and threatening the radiator. With a new bumper from Peter Debella and $13 worth of angle iron from the scrapyard, I mocked up a winch mount/skid plate that I welded right to the bumper:



The sun kept moving which made it a hot day to be cutting, grinding and welding.


Some welds coming together. Eventually all the welds get ground down for a nice smooth surface on the bottom and the top side that the winch will sit on. The orange angle iron above eventually gets cut into the side pieces that bolt to the frame via the original winch mount threaded inserts.


Winch mocked up. The lifting shackle brackets have since been modified and straightened to the frame. You can tell from some previous pictures that my frame horns were severely modified many years ago and I made no attempt to return them to factory. Since Bubba had completely removed the rise on the frame horns that would meet the inside of the top of the bumper, I simply made the bumper mount flat on top of the frame horns as they are now and the gap on the bottom of the frame horns to the inside bottom of the bumper is made up with cylindrical spacers. I ended up cutting off the protuding cylinders on the bottoms of the lifting shackles, since mine now mount nearly flush to the tops of the frame horns, and used those little bushings to make the spacers.


Pedal assembly was complete but needed rehab:


Where the brake pedal arm pivots on the pedal cross tube was very worn, so I drilled the arm out slightly larger, turned down the diameter of the cross tube, and made a sleeve that pressed into the arm. Drilled a hole for the grease to pass through and everything fits together with very little play now:


Like most steering sector arms, the tapered pins on mine were worn in only two spots, so I milled off the backside of the swadge that holds the pins into the sector arm, pressed them out, rotated them 90 degrees, pressed them back in, and cross drilled two roll-pins to help hold them in place:

Worn spots are now at 12 o'clock and 6 o'clock where the pins should now ride on the steering shaft worm gear around 3 and 9:


Milled off the swadging on the backsides of the pins. You can see one of the roll-pins on the right side bisects the pins at an angle running from about 1 o'clock through the pin:


Since I'm inbetween about a half-dozen things right now, I don't have many finished pictures of everything together but I'll work on getting some more pictures once it's all together. But this is is for now!