My old 1942 Willys has been in need of a refresh for a while now.....
This little guy is pushing 70 years old now so I figured it was time for a decent rebuild. Now, I don't want to hear any whining from the historical purists! This is a 1942 Willys MB, but it was never stock as long as I have owned it. I have tinkered with it for the last 8 years or so now. It is WAY too far gone to restore. Just like any much 'loved' jeep there is VERY little that is original. The specs as it sits currently are....
1942 Willys MB frame and body
1960s buick 225 v6 from a cj5 ( dual exhaust, HEI, holley 2bbl )
SM420 transmission ( 7.05:1 1st gear )
D18 t-case, twin stick, custom 1/2" long adapter to the transmission.
D44 rear axle from a cj5, 4.30 gears, powr-lok, 2pc axles
D25/27 front, 4.27 gears, disc brakes, crossover steering
Power steering conversion
hanging pedal conversion
70s GM column of some kind with a small steering wheel!
Overall its been a great little rig, but I have never fully trusted it. Its pushing 70 years now and I didn't do all the modifications. I found it in a field in Montana. The guy I bought it from got it from some guy who owed him money, who got it from the widow of the guy that did the major rebuid. That is how the story goes. I have tinkered with it for a few years now, but have always been on the fence about it. Its a cool piece of history, but its not worth restoring. Its been pretty much sitting around for over a year now. I finally hopped down off the fence and decided to rebuild it. I will be taking over the Rubicon late this summer/early fall........
The biggest overall problem with this old guy is that the frame is HAMMERED! The rear K-member is trashed. It looked like someone was using it to pull a bulldozer out with it. Once of the front frame rails is a little bent around the steering box. There is also some rusting at the rear shackle mounts. I debated for a long time about what to do. You can get a new original frame for around $1500 or you can get a box frame for about $2000+. Like everything else lately....I decided to make my own.
After a few dozen hours with a tape measure, some old FSM type manuals, and a few hour on the computer I came up with a simple frame.....
This rendering is not complete but shows the basic idea. The frame itself is constructed of 2x4 box tubing. The plates on the side define the critical measurements for the front and rear spring hangers. This will allow me to keep the frame very true when assembling it. I sent the side plates off to the laser cutter and ordered up two sticks of material. Total cost was less than $400 for everything shipped. The two sticks of material give me plenty for bumpers, cross members, and body mounts....
Update. ( I get a lot of requests for the frame print )
Still looking for a place to post the dxf/dwg for the side plates.
I had a member contact me about using the set of aluminum pucks I made to align the side plates and bolt the rails together when trimming the frame down.
Sadly I couldn't find the original set, I think I ended up turning them down into other things....
So...I made another set, this time out of some aluminum hex stock. This set will be traveling to the member who asked for them. The idea is when he is done he will either mail them back to me or onto the next person that needs them.
Now I am sure you are all wondering what it should look like when its done....
This is a photochop concept, from the Willys thread, I did of what I have in my brain....
One of the biggest problems that I have faced with this little guy is that the lack of wheelbase becomes a factor while doing stupid stuff like this.
Now, I don't totally want to ruin the character of this little guy by comp cutting the back and hanging the rear tire way out....or stretching the front way out with a way longer hood or whatever. I want it to still look like something from the late 40s or 50s.
When I was designing the frame I decided to give the frame a very moderate 'tasteful' stretch. I extended the wheelbase 3" in the back and 3" in the front. I also changed the front spring hanger location to use the longer rear springs in the front. I didn't want to go with super long springs like wrangler springs, or willys wagon springs simply because I think they would kill the performance in too many other areas. I will be keeping this keep VERY low to the ground overall. I think a low stance helps a vehicle perform better in most every way.
The new longer wheelbase will help me fit a larger tire front and back without having to lift the vehicle. The front of the rear tire gets pushed back in the wheel well a bit. The front tire moves forward giving more room behind it.
While it will never climb like a competition rock buggy, the low stance and 6" longer wheelbase should help a lot.
One of the things that bugs me most is that even when sitting basically on top of the fuel tank with ZERO padding under the butt, my head was still above the edge of the windshield. This requires a taller cage to protect your head, generally looks bad, and is just stupid. There has to be a better way....
So I ripped out the passenger seat and started measuring and experimenting. I found with the factory seats removed there was a lot of 'wasted' space that could be used for a 'better' seating position. I am planning on relocating the factory fuel tank and installing some better seats lower in the body tub with a slight cant to the rear. I'm 5'10" and in the pic I am sitting on about a 3-4" riser to simulate a much lower seat. I am leaning back just until I can see the leading edge of the hood......
Its a D20 transfer case. I will be using the case as a pattern for some parts I am building for the new frame. The D20 case is basically a stronger version of the D18 case. All the D20 cases have the larger 1.25" intermediate shaft. This will come in handy later if I want to run the Tera 3.15 low gearset. I also have an idea about adapting the SM420 with a short adapter to some 10-spline D18 overdrive parts ( since the SM420 uses a slightly larger 1.375" (?) 10 spline shaft )
I'm going to rip it apart tomorrow so I can model the case. I hope to make this information available in some CAD files or something. I am surprised that this information is not more common these days. I know these parts are older, but you would have thought someone would have posted an old blueprint or something?
I just got done tearing apart the Dana 20. Its nice to know you can take apart your t-case with just a few tools......
1/2" end wrench
9/16" end wrench
1 1/8" thin socket ( for the pinion yokes )
ball peen hammer
3/16" allen wrench ( for the shift forks )
That is about all you need to get it apart. The only thing that gave me a headache was the little allen set screws on the shift rails. Those things where VERY tight and a total pain to get to inside the case.
The good news is that the 1.25" intermediate shaft was in PERFECT shape with zero slop on the shaft, bearings, and thrust bushings. I will probably reuse it when I use the case for the upgrade. That saves a little coin.
I will clean up the case soon and start measuring for the 3D model. I hope I can at least get the front and rear bolt patterns done. That way people can at least have a chance to make there own adapters, cross members, and such.
One other tip: The closed end of the 1/2" end wrench fits over the teeth of the low range gears to allow you to 'lock' the t-case in order to get the drive shaft yoke nuts off with very little fuss. While not the super ideal way to do this....it does work in a pinch.
Well dang....two projects keeps me pretty busy....
I pulled the transmission out of the Willys today to swap in the replacement. The current transmission (sm420) was in the vehicle when I bought it. Its always had some issues, but it lasted the 8 years or so. This spring it finally gave up. I heard a bang when I pulled it out of the snow this spring....
Getting the transmission out was fun....not. The install by the previous owner was TIGHT. The v-6 is a little close to the firewall and high in the chassis. This made getting the tranny out HARD. I ended up having to trim the tunnel a bit to get the top of the bell housing down and out. Getting it back together is going to be fun.
ouch. The tunnel was heavily modified by the previous owner. I would suspect that the engine/trans/t-case was installed without the body tub on the chassis. I should be able to weld everything back to where it was when I get it all back together.
Here is the trans and t-case out of the jeep. Its sure compact. The 1/2" thick adapter is COMPACT for sure.
The front driveshaft uses a small style u-joint similar to the th400/d18 version. This is the only way the driveshaft u-joint can clear the transmission with the compact adapter.
Here is the factory twin stick shifter snugged up against the transmission. This thing BARELY fits. There is a custom shaft for the shifters that has a set screw on the end. I'm amazed it all fits.
Here are some shots of the 1/2" thick adapter plate. Boy it makes things TIGHT! It does give me a nice long drive line though....
This is the custom input gear....
It is made from a factory D18 input gear that is bored out and pressed over a turned down sm420 2wd drive shaft yoke....
The rear output bearing one the sm420 was destroyed. It must have rusted this winter and popped when I pulled it out for the first time this spring. I'm pretty sure it had been going out of a long time.
This is the adapter once you get the t-case off. Its a bit of a pain to get the t-case off! There are some trapped blind bolts that are a little hard to get out. I'm pretty amazed it all fits! Its almost like its factory since its so dang short.
That bearing is TOAST! You can also see some of the recessed bolts that hold the plate to the sm420.
I'll start putting it together tomorrow. I need to make some gaskets and take the t-case to the carwash!
Two 20' sticks of 2x4", 1/8" wall mild steel rectangular tubing. I think I see a replacement frame in there somewhere....
First I had to set up a simple jig for the big band saw. I printed out a drawing for the angle using a CAD program. Then I used a scrap of c-channel to build a fence so I could repeat the same angle over and over again.
It looks like this with a section of box tubing in it for a test cut....
Here is one of the laser cut 1/8" thick side plates. These are designed to set the spring hanger position into the frame design. The Willys is getting stretched out to an 86" wheelbase overall with a +3" front and rear. I will have the ability to move the axles front and back with some offset centering pins to tune the wheel position in the rear wheel well and overall resulting overall wheelbase in front.
I did a test cut on some scrap and this is the angle that was generated. This is more than close enough for an old willys frame. There will be a slight overlap for welding.
Now it was time to cut all the sections for the rails, the rear bumper, and front bumper.....
Sorry for the dark picture, but here are all the cut parts for the frame!
The frame design isn't the ultimate by far. You could make it a lot more complex. I am hoping that the mild (3 front, 3 rear )wheelbase stretch and bone simple 'rear' springs at all 4 corners will be enough for this old thing....
The frame design isn't the ultimate by far. You could make it a lot more complex. I am hoping that the mild (3 front, 3 rear )wheelbase stretch and bone simple 'rear' springs at all 4 corners will be enough for this old thing....
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