M274A4 Mule by Ben Connor

Want a practical Vietnam period vehicle, then I recommend an M274. I had an M274A4 mule, the best in my opinion. The Mule is small, fits perfectly in most long wheel based vans and best of all doesn’t take up all your garage space. Also no need for an MOT, Tax or even insurance (You would be silly not to insure it though).

Mule M274

I found myself a decent looking Mule on www.milweb.net, seller contacted, conversations had, realistic budgets agreed and viewing arranged. I drove down south to view the Mule. It was obvious from the first few minutes with it that it was a well maintained, dry stored and previously restored machine. Purchase made and Mule driven into my van.

So what is a Mule. The following information is directly from Wikipedia.

“The M274 Mule was introduced in 1956 to supplement both the 1/4 ton trucks (“Jeeps“) and 3/4 ton trucks (Weapons Carrier Series and M37 series) in airborne and infantry battalions. The M274 evolved from improvements to a vehicle designed at the end of World War Two by Willys-Overland as a medical evacuation litter carrier from areas and terrain that would even be a problem for its famous Jeep to access. Further tests by the US Army at Eglin Field, Florida proved it also useful as carrier for both supplies and men. In 1948 the US Army purchased a small number of these test vehicles with the designation the Jungle Burden Carrier for evaluation in jungle warfare and with airborne forces.[1] There were 11,240 Mules produced between their introduction and 1970, when production ceased. They were used throughout as platforms for various weapons systems and for carrying men, supplies, and weaponry/ammunition during the Vietnam War and in other U.S. military operations until the 1980s.

Mule M274

As a completely open and exposed vehicle, they offered absolutely no protection to the driver, yet that was relatively unimportant as they were mainly used as cargo carriers and medium-range infantry support vehicles, rather than tactical vehicles. The driver’s seat could be removed and the steering column moved forward and the vehicle driven in reverse to accommodate more cargo. If under fire the steering column could be moved farther forward and down, so the operator could operate the vehicle while crawling behind it. They were phased out from military usage in the 1980s with the introduction of the HMMWV series vehicles. The HMMWV was, however, unable to fulfill the role of the Mule, so the M-Gator, a military variant of the popular John Deere Gator vehicle, was introduced.”

My Mule was an M274A4. The A4 model is a converted A1 model. Some 1905 were built by Willys between 1962 to 1964 with AO4-53 4cylinder engine. The A4 conversion saw the A1 refurbished and an AO42 2cylinder engine fitted. Unfortunately, during the retro fitting work, the dataplate on mine was replaced to provide the details of the A4 however the serial and production date of the original vehicle was not transferred across.


All Mules have 3-speed manual, non-synchromesh transmissions with 2-speed transfer cases, and are 4-wheel drive vehicles. All Mules except the A5 variants had 4-wheel steering. Only the A5 variants had Electric Ignition as standard but lost the four wheel steer.

Mules have no suspension aside from the low-pressure tires and the seat cushions. There is a conventional style clutch, accelerator and brakes. What is unconventional is the lack of differentials, this is fine when going cross country but not so forgiving on tarmac. You basically don’t want to turn when on Tarmac unless you want to wear out the Tyres or damage the gears. You notice that the transmission is non-synchromesh, this means you select your gear, then pull away, you do not change gear whilst driving – this can actually have quite catastrophic results.


Buying a Mule isn’t just about owning a Mule. I have started collecting cargo, ammo crates, equipment to dress it for our shows. Because the M274 preceeded the Vietnam war through till the 80’s it is ideal to display.


As you can’t simply take a Mule to your regular garage I have learned all about how to maintain my M274. The right engine oil, filter, gear oil, the inspection and service intervals.


I use Golden Film SAE 30 Classic Motor Oil with 20% of Marvel Mystery Oil added.I use Millers Oils EP 80w-90 GL4 high quality gear oil for the Gearbox and drive components. For the Oil filter I use a Napa 1514. A little note on the Marvel Mystery Oil, it is added to Oil and Fuel. It reduces and prevents valve sticking and clatter by breaking down harmful deposits of carbon and sludge.  Mules often suffer from hydralic valves sticking and can be identified by a “ticking” sound coming from the engine compartment when the engine is running, not harmful.


As of December 2018 the mule has been replaced by a Dodge M37 in my collection