The M932 is a 5 ton truck made by AM General and later BMY for the US Military. It is a fairly current truck and still in use with the Army and Marines. The M939 series has many different models available from standard cargo trucks with 14' beds, with and without drop side beds and winches, M923, M924, M925 and M926. The M927 is a cargo truck with an extended wheelbase. The M934 also has the exended wheelbase and an expansible shelter (these look good, but are not really suitable for a camper build without extensive modification). The M929 and M930 are dump trucks and the M931 and M932 are semi tractors. These models have a short wheelbase. There have been revisions and updates to most of the models and there are A1 and A2 models in service.
The M939 family was built to replace the M809 series of 5 ton trucks built by AM General.
The newest version of these medium duty trucks with the military is the MTV family of trucks. These were initially made by Stewart & Stevenson and now made by BAE Systems and are cab-over designs. They are derived from the Austrian Steyr 12M18 trucks. The models include M1078 standard cargo truck, M1079 shop van, M1083/1084 5 ton cargo trucks, M1085/1086 long wheelbase cargo trucks and M1087 expansible van. These trucks have had some reported issues because of the different driving characteristics and extensive electronics in the engine and transmission.
The other side of these military trucks is the M35 series 2 1/2 ton trucks commonly known as deuce-and-a-halfs. These are slightly smaller trucks than the 5 ton versions and have half of the payload. The M35 has been made from the 1960's and are still in service in great numbers. They have gone through several revisions and updates and the current model is the M35A3.
The M35 is available in a variety of models including the M109 that is a common model to mod into a camper.
There are lots of things to consider when looking at these military trucks for use as an expedition camper. Often the trucks can be purchased at a very reasonable cost. Government Liquidators has auctions of trucks on a regular basis, however, you have to arrange pick up of the vehicle and often finding one close to where you are located can be difficult. The military trucks don't use many common commercial parts, although the M939 series does, and working on the trucks often takes heavy duty tools and can be a daunting task for someone without commercial diesel truck experience. Also, they are notorious for their lack of fuel economy and most models will get 10 mpg or less. Speed is not a consideration when the military purchased these trucks so don't expect to get anywhere in a hurry. The maximum safe (for the engine) speed is going to be about 50 mph.
I have spent the past several months in the same place you are and have been looking at various military trucks as the base for my expedition camper too. I have been looking at the M923 and M934 primarilly. However, after looking at the trucks and the pluses and minuses I'm now strongly leaning toward a more commercial vehicle like the Mitsubishi Fuso FG.
I hope this helps your quest. If you have any specific questions feel free to ask. Also the Steel Soldiers forum (also available on tapatalk) is a great resource for info on these trucks. The forums are in the "post Vietnam to Desert Storm" section.
Mike
