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'wittle 'wesistor (Mini Jeep)

6924 Views 152 Replies 6 Participants Last post by  remy_martian
For my next creation, I've been thinking about building a go kart sized jeep (mini-Jeep)
...but first, here is some Jeep info.

"The Jeep marque has been headquartered in Toledo, Ohio, ever since Willys–Overland launched production of the first CJ or Civilian Jeep branded models there in 1945. Its replacement, the conceptually consistent Jeep Wrangler series, remains in production since 1986. With its solid axles and open top, the Wrangler is the Jeep model that is central to the brand's identity.

At least two Jeep models (the CJ-5 and the SJ Wagoneer) enjoyed extraordinary three-decade production runs of a single body generation.

In lowercase, the term "jeep" continues to be used as a generic term for vehicles inspired by the Jeep that are suitable for use on rough terrain. In Iceland, the word Jeppi (derived from Jeep) has been used since WWII and is still used for any type of SUV.

Prior to 1940 the term "jeep" had been used as U.S. Army slang for new recruits or vehicles, but the World War II "jeep" that went into production in 1941 specifically tied the name to this light military 4x4, arguably making them the oldest four-wheel drive mass-production vehicles now known as SUVs. The Jeep became the primary light 4-wheel-drive vehicle of the United States Armed Forces and the Allies during World War II, as well as the postwar period. The term became common worldwide in the wake of the war. Doug Stewart noted: "The spartan, cramped, and unstintingly functional jeep became the ubiquitous World War II four-wheeled personification of Yankee ingenuity and cocky, can-do determination." It is the precursor of subsequent generations of military light utility vehicles such as the Humvee, and inspired the creation of civilian analogs such as the original Series I Land Rover. Many Jeep variants serving similar military and civilian roles have since been designed in other nations.

Development – 1. Bantam Reconnaissance Car
When it became clear that the United States would be involved in the European theater of World War II, the Army contacted 135 companies to create working prototypes of a four-wheel drive reconnaissance car. Only two companies responded: American Bantam Car Company and Willys-Overland. The Army set a seemingly impossible deadline of 49 days to supply a working prototype. Willys asked for more time, but was refused. American Bantam had only a small staff with nobody to draft the vehicle plans, so chief engineer Harold Crist hired Karl Probst, a talented freelance designer from Detroit. After turning down Bantam's initial request, Probst responded to an Army request and began work on July 17, 1940, initially without salary.

Probst drafted the full plans in just two days for the Bantam prototype known as the BRC or Bantam Reconnaissance Car, working up a cost estimate the next day. Bantam's bid was submitted on July 22, complete with blueprints. Much of the vehicle could be assembled from off-the-shelf automotive parts, and custom four-wheel drivetrain components were to be supplied by Spicer. The hand-built prototype was completed in Butler, Pennsylvania and driven to Camp Holabird, Maryland on September 23 for Army testing. The vehicle met all the Army's criteria except engine torque.

Development – 2. Willys and Ford
The Army thought that the Bantam company lacked the production capacity to manufacture and deliver the required number of vehicles, so it supplied the Bantam design to Willys and Ford, and encouraged them to enhance the design. The resulting Ford "Pygmy" and Willys "Quad" prototypes looked very similar to the Bantam BRC prototype, and Spicer supplied very similar four-wheel drivetrain components to all three manufacturers.

1,500 of each model (Bantam BRC-40, Ford GP, and Willys MA) were built and extensively field-tested. After the weight specification was revised, Willys-Overland's chief engineer Delmar "Barney" Roos modified the design in order to use Willys's heavy but powerful "Go Devil" engine, and won the initial production contract. The Willys version became the standard jeep design, designated the model MB, and was built at their plant in Toledo, Ohio. The familiar pressed-metal Jeep grille was a Ford design feature and incorporated in the final design by the Army.

Because the US War Department required a large number of vehicles in a short time, Willys-Overland granted the US Government a non-exclusive license to allow another company to manufacture vehicles using Willys' specifications. The Army chose Ford as a second supplier, building Jeeps to the Willys' design. Willys supplied Ford with a complete set of plans and specifications. American Bantam, the creators of the first Jeep, built approximately 2,700 of them to the BRC-40 design, but spent the rest of the war building heavy-duty trailers for the Army.

Final production version jeeps built by Willys-Overland were the Model MB, while those built by Ford were the Model GPW (G = government vehicle, P = 80" wheelbase, W = Willys engine design). There were subtle differences between the two. The versions produced by Ford had every component (including bolt heads) marked with an "F", and early on Ford also stamped their name in large letters in their trademark script, embossed in the rear panel of their jeeps. Willys followed the Ford pattern by stamping 'Willys' into several body parts, but the U.S. government objected to this practice, and both parties stopped this in 1942.

The cost per vehicle trended upwards as the war continued from the price under the first contract from Willys at US$648.74 (Ford's was $782.59 per unit). Willys-Overland and Ford, under the direction of Charles E. Sorensen (vice-president of Ford during World War II), produced about 640,000 Jeeps.

Jeeps were used by every service of the U.S. military. An average of 145 were supplied to every Army infantry regiment. Jeeps were used for many purposes, including cable laying, Sawmilling, as firefighting pumpers, field ambulances, tractors, and, with suitable wheels, would run on railway tracks."

https://en.wikipedia.org/wiki/Jeep

I came across this drawing
...& it seemed like a pretty good guide

So, I'm thinking maybe ~50% should work for a mini jeep
...so, I'll just have to calculate a ~2:1 reduction ;)

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They swapped out the front suspension to imorove the truck, then dropped the 7.3 for one engine disaster after another 🤦‍♂️

With the Jeepette's current front suspension design, am curious if you ever worked for Ford in the 1990's? 😂
 

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Discussion Starter · #123 ·
They swapped out the front suspension to imorove the truck, then dropped the 7.3 for one engine disaster after another 🤦‍♂️

With the Jeepette's current front suspension design, am curious if you ever worked for Ford in the 1990's? 😂
Um...it's a mini-Jeep (y)

I've been self-employed since I got out of high school
...but, I've worked on a "hell" of a lot of Fords :mad:

We ran Ford Tow trucks & Flatbeds (exclusively) for many, many years (but, never again)
...now, I just "run" an Isuzu NPR Flatbed (IMO a much better truck) ;)
* Better mileage, turning radius, quality, visibility, easier to maintenance etc.
 

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Discussion Starter · #124 ·
Steering Column
The steering column will be comprised of a 5/8" rod, a couple of pieces of steel tube (left over from making the front axle) a Pitman Arm & (3) plastic bushings (harvested from wheelbarrow wheels)
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I added the outer tube/bushing holder so it would look more like an actual steering coulmn
...& not, just be a steering wheel on the end of a rod.

* Notice, the upper bushing holder has upper & lower bushings
...& the lower bushing holder holds just (1)
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* I also, welded the Pitman Arm on to the steering shaft from the bottom side to keep the top side nice-n-clean, for "riding up against" the bottom bushing
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Discussion Starter · #125 ·
Steering Linkage
The steering linkage is composed of a Tie Rod (& ends) that connect the Pitman Arm (arm on the bottom of the steering shaft) to the left Spindle Arm (arms on the spindle)
...& also, a rod (& ends) that connects the left spindle to the right spindle.
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* Note:
If the Spindles are "set up" with the Arms oriented in a Leading fashion (with connections ahead of the wheel &/or toward the front)
...then, the Pitman Arm also must be oriented in a Leading fashion (with connections ahead of the steering shaft &/or toward the front)
or
The steering "action" will function backwards
...&/so, "if" you turned the steering wheel toward the left, the wheels would turn toward the right. :eek:

Another surprise inspection? :unsure:
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He was "cat nappin" just 5 min ago :p
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Internet cat pics 🤦‍♂️ - I thought this would a safe place against that 😉

The tie rod running the full width of the car seems a bit weird vs having two rods off the pitman arm.

A failure of the pitman rod, the way you have it, means a total steering loss, though the wheels stay nice and parallel as they take you into a tree.
 

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Discussion Starter · #127 ·
Internet cat pics 🤦‍♂️ - I thought this would a safe place against that 😉

The tie rod running the full width of the car seems a bit weird vs having two rods off the pitman arm.

A failure of the pitman rod, the way you have it, means a total steering loss, though the wheels stay nice and parallel as they take you into a tree.
Well, um...that's how the steering linkage is set up on these Solid Axle old style Jeeps (& other solid axle 4 x 4's too) :cool:
...even the steering linkage, on my Isuzu NPR Flatbed Tow Truck is set up, like this
...& IIRC Ford Super Duties too (both 2 WD & 4 WD) :)

FWIU the individual Tie Rod concept is necessary for vehicles with independent suspensions
...but, a failure of either "way or style" the Brake system should still function ;)
...&/so, most folks would just use the brakes to STOP the vehicle before hitting the tree (y)
 

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Discussion Starter · #129 ·
Interesting. But don't they also have idler arms?
Um...I'm not 100% for sure
...but, not that I remember

IIRC Idler Arms are usually necessary on/for vehicles with IFS (2WD &/or 4WD)
...also, IIRC an idler arm's main purpose (on vehicles with IFS) is to support/hold up, the "other end" of the linkage
(the end that's not supported by the Pitman Arm) (y)

* There are some Jeep guys here, on the forum
...maybe they can "chime in" with info, on the subject :p

** Using (2) individual Tie Rods, (1) from the Pitman Arm to each Spindle, would/could cause (&/or increase the chances of) a phenomenon referred to as "Bump Steer" (Google it) ;)
 

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I know all about bump steer - like an idiot (mid teens) I wanted the drag car look so I replaced the IFS on my car with a leaf spring beam axle to lift the car's front end.

Some, not all, of that idiocy annealed out with experience, learning (I've attended engineering school and The School of Hard Knocks), and time.
 

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Discussion Starter · #131 ·
I know all about bump steer - like an idiot (mid teens) I wanted the drag car look so I replaced the IFS on my car with a leaf spring beam axle to lift the car's front end.

Some, not all, of that idiocy annealed out with experience, learning (I've attended engineering school and The School of Hard Knocks), and time.
That "look" was popular, way back when
...& as long as you learned from it (ya learned from it) ;)

Notice, the "tabs" that I included, on the floor board, for connecting to/with adjacent panels
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...& here is how the front end, of the floorboard (& lower steering bushing) will be supported
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...& here is about how, the steering column will look, protruding out from under the dash/cowl :)
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Discussion Starter · #134 ·
I used my CAD "program"
...to produce a Rear Inner Fender Lid😁
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I can use the template, to make another (more many, many more He...He...He...um...moving on) :unsure:

This (1) would be for the right side (part # MJ-78926-75-R)
...& just flip it over for the left side (part # MJ-78926-76-L)
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After a little bit of folding, we have something like this ;)
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Here is about where they will go :)
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...& how they will look :cool:
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Um...the inspector is "sleeping on the job" again
...maybe we can "classify" him as cargo? :p
 

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Discussion Starter · #135 ·
After the inspector finished his nap, I was able to get the rear inner fender (wheelwell) lids installed :)
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About how the rear inner wheel wells are fabricated & look, in a FS Jeep
...& seem like they will be easy enough to replicate (using these cardboard templates) out of metal ;)
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Discussion Starter · #137 ·
Those inner rear fenders might make nice jump seat bases....

Assuming your springs are up to it.

That may set your gage a bit thicker than you normally would, if you decide to go with that capability.
Hey Remy,
Yes, I agree.

These style of Jeeps (military & civilian) were modified 1000's of different ways
...in the military (out in the "field") they modified them for what they NEEDED (wounded carrier, armored etc.)
...in civilian use they were modified for "the job" like farm-work as a gas-powered horse (for pulling plows & wagons etc.)
...& even for industrial use (like mounted generators & welders for use "out in the field", on construction sites etc.)

* I'm almost thinking maybe modify it to be a go kart mini-tow truck :cool:

I know a guy, who has a bunch of karts
...& may be able to use a "mini-tow" from time to time ;)

Springs?
...I may need to make some mini-helpers :giggle:
...or mini Timbrens :p
 

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Discussion Starter · #140 ·
Moving on to the front

I CAD 'ed up a mini-Jeep Hood :)
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...but, before we can design/make the grille, we gotta "nail down" the exact "look" that were going for, like
...old Military (M38)
...new'er military (M38A1)
...old civilian (CJ5) or (CJ7)
...new'er civilian (Wrangler)

* Remember, they all had basically the same body (late 40's thru Um...well, kinda now) ;)
...so, to keep my range of options as "wide open" as possible, I'm thinking this "will be" one of those surplus Army Jeep's (like a "flat fendered" M38) that someone bought, back in the late 60's/early 70's (as a personal commuter)
...& then, customized it :p

This way I'm NOT "locked in" to any specific "period" correct-ness BS
...like, the look of the steering wheel or rims & tires or seats or color or even upgrades & modifications :cool:
 
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