1942 Willys MB 'slat grille'

After securing the contract to manufacture the WWII quarter-ton truck, Willys produced the early Willys MA model, which evolved into the Willys MB. These initial MB jeeps, built from November 1941 to March 1942, are recognized for their unique “slat grille” made from iron bar stock. This distinctive feature, limited to the first 25,808 units, was later replaced by Ford's stamped steel grille design, which reduced production time and weight while incorporating airflow deflectors.

Differences

The slat grille MB differed significantly in both structure and functionality compared to later models. Early models lacked a glove box, meaning components like the fire extinguisher were mounted near the passenger side toe board. Early production also used a shorter windshield frame, which was later extended by two inches to accommodate taller drivers. Up to truck no. 164,554, the windshield featured push-button fasteners for the canvas top and uniquely placed hold-down catches to secure the windshield in its folded position. Other distinguishing features included the brass data plates, a solid black plastic steering wheel, and a speedometer graduated in 5 mph increments, along with a fuel gauge labeled “GAS” instead of “FUEL.”

The vehicle's body design included several unique elements, such as two separate small hinges on the toolbox lids instead of a continuous hinge, and locks keyed to match the H700 ignition key. The slat grille MBs were also distinct for their fuel tank well, which was box-shaped rather than rounded as seen in later models. The early jeeps did not include certain accessories, such as trailer light sockets or fuel can carriers, until mid-1943. Another distinctive feature of the slat grille jeeps was the use of rubber parts, including rubber shifter boots, seals around the fuel tank, and rubber hood blocks, which were later replaced with wood as wartime material rationing increased.

Mechanically, early MB models were prone to veer to the left during heavy braking due to the axle-mounted bell crank, which was later corrected with the addition of a torque reaction spring to the driver’s side front spring. The frame and suspension also included early design traits, such as solid disc wheels on pre-standardized units and early Kelsey-Hayes solid wheels used until truck no. 120,700. The AC Spark Plug Co. provided a distinctive “hat style” air filter for these early jeeps, which was later replaced by the Oakes model in subsequent versions.

The slat grille MBs came with various specialized components not found on later models. For instance, the fuel tank was equipped with a narrow neck that required a smaller cap, and the exhaust system initially used a round muffler before switching to an oval design. These jeeps also had a Holland Hitch Co. T-60-A pintle hook without trailer safety chain eye bolts, which were added in later production.

Restoration of these early jeeps is often a painstaking process due to the scarcity of original parts and the intricate details unique to each production phase. Due to their unique features and limited production run, the slat grille MBs have become a rare and prized collector’s item.

Fun Fact: Grille or Grill?

Collectors and enthusiasts seem to use the two terms interchangeably have you ever wondered which is correct? 

Grammatically speaking, “grill” — both as a verb and as a noun— relates to cooking food over a metal structure placed over a fire.

“Grille,” on the other hand, refers to a metal structure of bars built around or across something to ensure its protection.  

Based on that, the thing protecting the radiator on either a Willys or Ford Jeep is a "grille."  

But if you really want to be correct, Ord 9 SNL G-503, List of Service Parts for Truck, 1/4-ton, 4x4, Command Reconnaissance (Ford Model GPW; Willys, Model MB), refers to that protective piece in front of the radiator as neither. Instead, it labels it as a "guard" (part number WO-A3615).