The M38 isn’t very well known outside of collector, fanatic or Jeep Owner circles. Visually similar to its predecessor, the WWII era Willys Model MB Jeep, the M38 Model MC really is a different truck. It is as if Willys sat down with WWII Jeep drivers and asked for a laundry list of things that they’d like addressed in a new truck model. The M38 is the result of incorporating these ideas.
The Model MC is slightly larger, offering greater room for the driver and boasting an improved transmission. Casual inspection shows the M38 differs from the WWII-era Model MB with a one-piece Windshield Glass, Tailgate, larger tires, protruding Fuel Filler on the body side, larger and bulging Headlights where the earlier Jeeps had recessed units and Pioneer Tool stowage relocated to the right side. The M38 Jeep, like other post-WWII tactical trucks, had a 24-volt electrical system and was the first Jeep to have such – where the WW II Jeep had a 12-volt system. The Model MC Jeep carried a battery under the Hood and a second battery in a compartment inside the cowling in front of the passenger. Willys produced 45,373 Model MC Jeeps between 1950 and 1952.
In the historical photo at right, the Willys WW II-era Jeep is center left, with the M38 Model MC at center right - you can better see the size difference between these two trucks. General Data: Willys Model MB and MC Jeeps Both the Willys Model MB and Model MC Jeeps have an 80-inch wheelbase in common . They look alike in many areas too, further encouraging the effort. However, the similarities between the two trucks diverge from a common wheelbase, and parts from the two trucks are not directly interchangeable in most cases. While not intending to belabor the point further, I’ll list some of the differences between the two trucks below.
Tires: The WWII Model MB Jeep used 6-ply, 6:00 x 16 NDT (Non-Directional Tread) tires. The Model MC M38 Jeep used larger 6-ply, 7:00 x 16 NDCC (Non-Directional Cross Country) tires from GoodYear and BF Goodrich. Both trucks could be seen with Combat Tire/Rim combinations in service – but note that only the M38 Jeep prototypes commonly used Combat Tire/Rim combinations. The M38 Jeep used special steel safety rims. The tires mounted on the M38 Jeep coming out of the factory were NDCC-types from thetwo suppliers above. Also fitted during its service; Cooper, Firestone and Seiberling Special brand tires could be found on the M38 Jeep. Can the M38 Jeep run on the smaller WWII era tires? Yes, they can be fitted to the M38 Jeep, with penalty being a rougher ride for the occupants. The M38 Model MC Jeep’s frame is a heavier than the Model MB Jeep – beefier springs and better reinforced, with a different rear cross-member.
Angle of Approach: Looking at the two trucks from the front, the M38 Model MC has a 55-degree angle of approach (AoA), compared respectively with the WWII-era Model MB Jeep’s 45-degree AoA. Ground Clearance: The M38 Model MC’s Ground Clearance is 9.25-inches, compared to the 8.75-inches in the Model MB. Overall Length: The M38 Model MC Jeep is 133-inches long with the spare tire fitted. The Willys Model MB Jeep is 132.25-inches in comparison. Inner Wheel Track: Model MB Jeep is 42.5-inches, as opposed to 41 3/8-inches in the M38 Model MC Jeep. The difference is mostly due to the wider tires fitted to the M38 Jeep.
Tread Center-to-Tread Center: The Model MB Jeep is 49-inches, as compared to 49 3/16-inches in the M38 Model MC – again difference is mostly due to wider tire width on the M38. Outer Wheel Track: Model MB Jeep equals 55.5-inches, compared to 57-inches in Model MC – same as above for the difference. Note: An even more esoteric difference between the two trucks; the wheels on the Model MB Jeep track inside each other, with a 49-inch span (Tread Center to Center). However, the Front Wheel track, center-to-center, on the M38 Model MC Jeep comes in at 49 1/8-inches – and 49 3/16-inches at the rear; cutting a slightly wider track at departure. The Bumper Mounts themselves are different on the M38 Jeep – the gussets (small triangular braces) found on the WWII Model MB are not present in this variant, having been replaced with stamped versions. The Front Bumper/Rear Bumperette combination is similar between both vehicles. The M38 Jeep’s Front Bumper is 46-inches wide, with 45-degree back-cuts on the ends. The L-Head (Go Devil) side valve Engines are similar, with some parts different in the M38 as compared to the Model MB. The Model MC Jeep had a factory-installed, fully waterproofed ignition system and could be fitted with a Deep Water Fording Kit. This combination of factory-installed and additional user-installed DWF Kit allowed the M38 Jeep to drive through water up to 74-inches deep – which is over the top of the truck’s windshield. The Willys Model MB could not perform in this manner from the factory. Speaking of performance, neither Jeep Models were particularly fast – likely 55-mph maximum safe on improved roads.
Body Tub - The Body Tubs are similar in overall appearance as stated above, but the Pioneer Tools stow on the opposite side on the M38 Jeep. There is no Fuel Tank well on the M38 Jeep, and the front floor reinforcing channels are simpler as result. Instead of having to prop-up the Driver’s Seat to refuel the Model MB WWII Jeep, the M38 has Fuel Filler protruding through the left panel. With the larger Body, the driver has a little more room to position the seat back from the Steering Wheel, increasing comfort for “larger” soldiers. The M38 Jeep’s Body Tub floor does not have a protruding riser panel for a Machine Gun mounting as found on the WWII Jeep – as there was no MG Mount present on the truck as delivered from the factory. When the operators of the M38 Jeep in the field equipped their truck with a Machine Gun, it was fitted with a slightly different tripod-style mount (Mount M31A1) than found on the Willys Model MB Jeep – that also called for a center reinforcement plate to be set underneath the Tub floor between it and the Frame. There are no toolboxes mounted inside the rear wheel wells of the M38 Jeeps like found on the WWII Model MB Jeep, but the M38 does have a large bin underneath the passenger seat for such storage. The M38 Jeep has a Tailgate, where the Model MB does not. The Tailgate has reinforcements mounted on it to handle the extra weight of both the Jerry Can and Spare Tire. In US Air Force service, the spare tire was relocated to the right side of the truck, affording uninterrupted use of the Tailgate on their M38 Jeeps. I am aware that civilian versions of the CJ-3A have the manufacturer’s logo WILLYS stamped on both sides of the Hood – but I have not seen this feature on the military M38 as delivered from the factory. Collectors and restorers look for this feature to help determine authenticity on their trucks.
Another interesting note from collectors and restorers of these Jeeps; the early M38’s had five Data Plates that each individually screwed directly to the Dashboard. After 9/1951 and Serial Number MC34151, they were mounted on a separate plate – that was then screwed to the Dashboard. As delivered by another company, the Instrument Panel (complete with Gauges) came pre-painted. However, the Olive Drab color the supplier used didn’t match the Willys Body Tub and Chassis/Frame color. The Steering Wheel on the M38 Jeep is OD Green, not Black, if you were wondering. The Rear Bench Seat is usable too. M38 Jeeps came with full canvas tops and side-curtains, and folding canvas doors. If you ever come across a photo or a restored M38 Jeep, and notice a length of chain welded to the Body Tub near the Steering Wheel – this is an old military solution to preventing the Jeep from being easily stolen. The chain is wrapped around one of the spokes on the Steering Wheel, and then padlocked. The Windshield Frame on the M38 Jeep is taller than found on the WWII era Model MB. This feature is intended to give taller drivers ability to see out of the windscreen without having to crank their necks downward. The M38 Jeep came with 4-inch thick seat cushions, as compared to the 2-inch thick cushions in the WWII Jeeps – important for driver comfort. However, the extra comfort afforded by the thicker seat cushions negated the benefit of the added height of the Windshield Frame for taller M38 Jeep drivers.
The M38 Jeeps have vacuum-operated Windshield Wipers, where the WWII Jeeps are equipped with linked manually operated Wipers. The Windshield Wipers on the M38 are mounted on the bottom of the windshield glass. When the Arctic Kit is installed, the Wipers are mounted to the top of the Windshield Frame, and there is a long duct placed in the motor’s former position intended to blow air across the bottom of the glass for defrosting. The M38 Jeep’s Hood has wooden riser blocks for bracing the Windshield Frame when folded down forward. Another easily seen feature difference is the prominent Grill. The Willys Model MB has a 9-slot Grill. So do the six prototype M38 Jeeps, known as Model MC-38 Jeeps. The standardized Model MC Jeeps have 7-slot Grills, with hinges on the bottom that allow the Grill to be folded down forward for pulling out the Engine in one piece to service or replace. The Headlights on the M38 Jeep are larger than their WWII cousins, and protrude from the Grill, where the Model MB’s are recessed behind the Grill. The Headlights on the M38 had Guards mounted diagonally in front of the lens, almost giving the M38 a slant-eyed look from certain angles. The provided markings are for US ARMY 20890493 and US ARMY 20944323 – which do fall into the proper registration range for the M38 Jeeps. Historically speaking, seven-digit Hood Registration Numbers ran from 236xxxx through 238xxxx from 9/1950 to 5/1951. After 5/1951, M38 Jeep Registration Numbers were eight-digits long, running from 208xxxxx through 209xxxxx. For the time period, M38 Jeep numbers and lettering appear to be mostly, and neatly, handpainted – stencils not used in most cases, or the stencils were used and the lettering/numbers filled in neatly.