6x6 Diamond T cargo truck using its front-mounted winch to extricate itself during Motor Transport training at Camp Crowder, Missouri.

6x6 Diamond T cargo truck using its front-mounted winch to extricate itself during Motor Transport training at Camp Crowder, Missouri.

The 4-ton Diamond T trucks were originally developed at the behest of the Quartermaster Corps to serve as a prime mover for the 155mm howitzer. However, due to the success of these trucks, they were soon adapted to other roles as well.

Early models of these trucks were all built in the closed-cab version of the Diamond T chassis. While the hood and fenders were strictly military, the cab itself was based on Diamond T’s commercial truck cabs. During June and July of 1943, this was replaced with the military-style open cab, which allowed greater visibility and better air defense.

A Hercules RXC 529-cid inline six-cylinder engine powered most of these trucks. The high-torque engine and low gearing of the five-speed transmission and two-speed transfer case allowed a highway towed load rating of 12 1/2 tons.

967, 968, 968A, & 968B Cargo Trucks

Truck Cargo SWB 4ton 6x6 Diamond T photographed during Tanks in Town in Mons, Belgium, 2011. Early versions had a closed cab. Beginning in June 1943, open cab production began. 

Truck Cargo SWB 4ton 6x6 Diamond T photographed during Tanks in Town in Mons, Belgium, 2011. Early versions had a closed cab. Beginning in June 1943, open cab production began. 

These trucks were referred to as short wheelbase trucks and were intended to transport personnel, general cargo, or to act as a prime mover for 155mm Howitzers. Like almost all the WWII cargo trucks, the beds of these trucks initially were made of steel, but were changed to wood construction early on. The two spare tires were carried across the front of the bed.

The identifying feature of the 967 4-ton 6x6 Diamond T is the brush guard that protects the radiator and headlights.

The identifying feature of the 967 4-ton 6x6 Diamond T is the brush guard that protects the radiator and headlights.

The Model 968 was fitted with a larger, more powerful Hercules RXC engine

The Model 968 was fitted with a larger, more powerful Hercules RXC engine.

The Model 967, produced in early 1941, was first in the Diamond T series and was powered by the Hercules RXB 501-cid inline six-cylinder engine. The 967 is easily distinguished by its one-piece brush guard, which extends to protect the headlamp. Later models have a narrower brush guard, with separate guards for the headlights.

The Model 968, introduced later in 1941, was upgraded to the larger, more powerful Hercules RXC engine.

The Model 968A, which began production in November 1941, featured the military-type instruments instead of the civilian style used previously.

The Model 968B was the final version of the short wheelbase 4-ton Diamond T.

Diamond T 968s in Plauen, Germany, 1945.  

Diamond T 968s in Plauen, Germany, 1945.  

G-509 Cargo Truck Specifications

Diamond Ts in the Long Binh Depot PDO yard in 1965-66.

Diamond Ts in the Long Binh Depot PDO yard in 1965-66.

ENGINE MAKE/MODEL: Hercules RXC
NUMBER OF CYLINDERS: 6
CUBIC-INCH DISPLACEMENT: 529
HORSEPOWER: 106 @ 2300 rpm
TORQUE: 342 lbs.-ft. @ 900 rpm
GOVERNED SPEED (rpm): 2300
NET WEIGHT: 18,450 lbs.
GROSS WEIGHT: 34,500 lbs.
MAX TOWED LOAD: 25,000 lbs. 
LENGTH: 297 
WIDTH: 95.25 
HEIGHT: 119
WIDTH*: 50/94 
TRACK: 72 
TIRE SIZE: 9.00-20 
MAX SPEED: 40 mph 
FUEL CAPACITY: 60 gal 
RANGE: 180 mi 
ELECTRICAL: 6/12 pos 
TRANSMISSION SPEEDS: 5
TRANSFER SPEEDS: 2
TURNING RADIUS FEET: 37.5 R, 39 L 
Overall dimensions listed in inches.
* Inside/outside width at tires.

You may also enjoy

*WWII Diamond T 4-ton Wrecker

*Can you identify these military Jeeps? 

*G-630 Studebaker: The other WWII 2-1/2-ton truck

*As an Amazon Associate, Military Trader / Military Vehicles earns from qualifying purchases.

Frontline Feature

MLT SPOT FOR SALECROP

UP FRONT AND CENTER!

This Spot Reaches More than 10,000 people a day.