View source for 2½-ton 6×6 truck

{{short description|Class of military medium duty trucks}}
{{Use American English|date=November 2024}}
{{Use dmy dates|date=November 2024}}
[[File:Red Ball Express - Truck in the mud.jpg|thumb|A [[Red Ball Express]] truck gets stuck in the mud during World War II, 1944.]]
[[File:M35A2 with winch.jpg|thumb|1971 AM General M35A2 with winch and camouflage cargo cover]]
The '''{{frac|2|1|2}}-ton, 6×6 truck''' was a standard class of medium duty trucks, designed at the beginning of [[World War II]] for the [[United States Armed Forces|US Armed Forces]], in service for over half a century, from 1940 into the 1990s.{{refn |group=nb | Originally, during World War II, categorized as a ''light-heavy'' truck.<ref name=HydeArsenal/>}} Also frequently known as the '''deuce and a half''', or just '''deuce''', this nickname was popularized post WWII, most likely in the [[Vietnam War]] era.<ref>[http://usautoindustryworldwartwo.com/General%20Motors/gmc.htm The American Automobile Industry in World War Two (2-1-2019)]</ref> The basic cargo versions were designed to transport a cargo load of nominally {{convert|2+1/2|ST|lb kg}} over [[All-terrain vehicle|all terrain]], in all weather. The {{frac|2|1|2}}-ton trucks were used ubiquitously in World War II, and continued to be the U.S. standard medium duty truck class after the war, including wide usage in the [[Korean War|Korean]] and [[Vietnam War]]s, as well as the first [[Gulf War]].
Originally, five different designs were standardized by the U.S.; two were also standardized by [[Canadian Armed Forces|Canada]]. During World War II the most important model for the U.S. Army was the [[GMC CCKW 2 1/2-ton 6x6 truck|GMC CCKW]]  or "'''Jimmy'''", with over 560,000 units built. Another 200,000+ deuces were [[Studebaker US6 2 1/2-ton 6x6 truck|Studebaker and REO US6]], built primarily for [[Lend-Lease]] export, mostly to the [[Soviet Union]], and many others have been exported to smaller militaries. In addition to the 6x6 trucks, a significant minority of these trucks were also built minus the front-wheel drive, as 6x4 trucks.<ref group=nb>The term [[Six-wheel drive|"six by six"]] must not be taken too literally—the vast majority of the {{frac|2|1|2}}-ton trucks had ten wheels—what is meant is three axles, with driving power being available to all six axle-ends.</ref> The nickname "Jimmy", a phonetical diminutive of GMC, could be applied to both their 6x6 and 6x4 units.
After World War II, the [[M35 series 2 1/2-ton 6x6 cargo truck|M35 series truck]], originally developed by [[REO Motor Car Company|REO]], became the standard {{frac|2|1|2}}-ton truck. First fielded in the 1950s, the M35 family became one of the most successful and long-lived series of trucks ever deployed by the U.S. military. They were used in Vietnam and continued to be used with various modifications into the late 1990s.<ref name=OD_M35>{{Cite web |url=http://ftp.olive-drab.com/od_mvg_www_deuce_m35.php |title=M-35 Series 2 1_2-ton, 6x6 Trucks (G-742) – Olive-Drab |access-date=2018-07-20 |archive-date=2018-07-20 |archive-url=https://web.archive.org/web/20180720102133/http://ftp.olive-drab.com/od_mvg_www_deuce_m35.php |url-status=dead }}</ref>
In 1991, the U.S. military began replacing the {{frac|2|1|2}}-ton, ten-wheeled (6x6 and 6x4) trucks, that were originally classified as "light-heavy" in WW II, and "medium duty" later in their service life, with a significantly different design: the four-wheeled (4x4), [[Cab over|cab over engine]] "light medium", but equally {{frac|2|1|2}}-ton rated, LMTV variants of the [[Family of Medium Tactical Vehicles]] (FMTV) .
Of the almost 2.4 million trucks that the U.S. Army bought between 1939 and December 1945 (across all payload weight classes), just over one third (~812,000) were {{frac|2|1|2}}-ton trucks, the vast majority of which (over 675,000 units) were six by six variants—outnumbering the almost 650,000 [[Willys MB|World War II jeeps]].<ref name=HydeArsenal>{{cite book |last=Hyde |first=Charles K. |year=2013 |title=Arsenal of Democracy: The American Automobile Industry in World {{nobr|War II}} |url=https://books.google.com/books?id=P-PCAgAAQBAJ&pg=PA152 |publisher=Wayne State University Press |pages=152–153 |isbn=978-0-8143-3952-7 |ref=HydeArsfn }}</ref> A further ~118,000 {{frac|2|1|2}}-ton trucks were built as 6x4 driven units.
The {{frac|2|1|2}}-ton cargo truck was considered such a valuable piece of equipment that [[Dwight D. Eisenhower|General Eisenhower]] wrote that most senior officers regarded it as "one of the six most vital" U.S. vehicles to win the war.{{refn |group=nb |name=IkeQuote |The others being the [[bulldozer]], the [[Landing Ship, Tank]], the amphibious [[DUKW|"Duck"]] truck, [[Willys MB|the jeep]], and the [[C-47 Skytrain|C-47 airplane]].<ref name=IkeCrusade>{{cite book |author=Dwight D. Eisenhower |year=1948 |title=Crusade in Europe |url=https://books.google.com/books?id=WGQLGxE8LyAC&pg=PA164 |publisher=Doubleday (US)/Heinemann (UK) |page=163/164 |isbn=978-0-8018-5668-6 |oclc=394251 |author-link=Dwight D. Eisenhower}}</ref> }} It has been called the most important truck of World War II, and the 6×6 became known as the "workhorse of the army".<ref name=HydeArsenal/> According to Hyde (2013): "Each of the three axles had its own differential, so power could be applied to all six wheels on rough terrain and steep hills. The front axle was typically disengaged on smooth highways, where these 'workhorses' often carried loads much above their rated capacity."<ref name=HydeArsenal/>
Half a century after World War II, the remanufactured {{frac|2|1|2}}-ton M35 trucks still met 95 percent of the performance requirements at 60 percent of the cost of a new [[Family of Medium Tactical Vehicles|FMTV vehicle]].<ref name=OD_M35/>
==History==
[[File:Army vehicles on a road in Belgium.jpg|thumb|U.S. Army vehicles on a road in Belgium, 19 January 1945]]
In 1939-1940 the [[United States Army Ordnance Corps|U.S. Army Ordnance Corps]] was developing a {{frac|2|1|2}}-ton (5,000&nbsp;lbs, 2,300&nbsp;kg) load-rated [[six-wheel drive|6×6]] tactical cargo truck that could operate off-road in all weather. Dump, semi-tractor, tanker, and other bodies were also planned.{{sfnp|Crismon|2001|p=8, 326-327, 329}}{{sfnp|Ware|2014|p=236, 238-239}}
[[Yellow Coach Manufacturing Company|Yellow Coach]] (a [[General Motors|GM]] company), [[Studebaker]], [[International Harvester]], and [[REO Motor Car Company]] submitted designs, all except REO's were accepted and in production by 1941. Yellow's CCKW became the Army standard, International's M-5-6 became Navy and Marine Corps standard, and Studebaker's US6 was built for export to allied countries. REO built the Studebaker design.{{sfnp|Ware|2014|p=236, 238-239}}{{sfnp|Crismon|1995|pp=164-165}}{{sfnp|Crismon|2001|pp=327-334}}{{sfnp|Doyle|2003|pp=108, 122, 125}}
In the late 1940s the military needed a new standard truck. Chrysler, GMC, REO, and Studebaker submitted designs. The REO design was standardized for all services as the M35, and continued standard until 1990. The GMC was classed as substitute standard M135 in the US but became standard in Canada.{{sfnp|Crismon|2001|pp=335-338}}{{sfnp|Doyle|2003|pp=127-128, 156}}
==Designs==
===GMC CCKW===
[[File:GMC_CCKW-353 Truck, 2.5-ton, 6x6, Cargo w-Winch, USA 497253 S pic1.JPG|thumb|right|GMC CCKW]]
{{main|GMC CCKW 2 1/2-ton 6x6 truck}}
As the standard US Army design during World War II, over 560,000 were built, more than any other US vehicle except the [[Willys MB|"Jeep"]]. By 1947 there were over 20 standardized bodies, and many more special modifications.
Production began at Yellow Coach's [[Pontiac, Michigan]] truck plant in 1941 and at Chevrolet's [[St. Louis]] plant in 1942. In 1943 Yellow was renamed G.M.C., leading to the popular nickname "Jimmy". Production ended in 1945.
Early trucks had GM's standard closed cab, from July 1943 military open cabs, which were easier to build and lowered shipping height, were used. To conserve steel, later cargo bodies were built largely of wood. The [[Cab over|C.O.E.]] AFKWX, 6x4 CCW, and amphibious [[DUKW]] were mechanically virtually identical and were built next to CCKWs in both plants.{{sfnp|Crismon|2001|pp=330-334}}{{sfnp|Doyle|2003|pp=105-121}}{{sfnp|Hyde|2014|pp=203-207}}{{sfnp|Ware|2014|pp=237-239}}{{sfnp|TM 9-801|1944}}
===Studebaker US6===
[[File:Studebaker US.jpg|thumb|right|Studebaker US6]]
{{main|Studebaker US6}}
The US6 was very similar in layout to, and shared some components with, the CCKW. Studebaker built over 195,000 at their [[South Bend, Indiana]] plant between June 1941 and August 1945, REO built another 22,000 in 1944–1945. The majority were exported Lend-Lease to the Soviet Union.
Early trucks used a commercial style closed cab, in December 1942 an open military style cab  entered production. The Soviet Union preferred the closed cabs for their extreme weather, so in March 1943 the open cabs were discontinued, after only about 10,000 were built.
The Studebakers were very successful in the Soviet Union, where they carried large loads on poor roads in extreme weather. They were so successful that they were closely copied as the [[ZIS-151|ZIS-/ZIL-151]] and [[ZIL-157]] family of trucks, built in the USSR until 1966 and in China until 1986.{{sfnp|Crismon|2001|pp=328-329}}{{sfnp|Doyle|2003|pp=122-124}}{{sfnp|Ware|2014|p=111, 181}}{{sfnp|Hyde|2014|pp=65-67, 208-209}}{{sfnp|TM 9-807|1943}}
===IHC M-5-6===
[[File:International M-5H-6.jpg|thumb|right|International M-5H-6]]
The International design began production at [[Ft. Wayne, Indiana]], in 1941. 500 M-5-6s and 3,000 M-5-6x4s, with a commercial K model cab, were complete by 1942, and were exported to the Soviet Union. The design then was upgraded, with a larger engine, tires, military open cab, and other improvements, and standardized as the M-5H-6 for the US Navy and Marines. The only {{frac|2|1|2}}-ton with locking differentials, it had excellent off-road performance. More than 30,000 of all models were built between 1941 and 1945.{{sfnp|Crismon|1995|pp=164-165, 170, 178, 185, }}{{sfnp|Crismon|2001|pp=327-328}}{{sfnp|Doyle|2003|pp=125-127}}{{sfnp|Hyde|2014|pp=209}}{{sfnp|Ware|2014|p=236}}
===REO M35===
[[File:M35.jpg|thumb|right|REO M35]]
{{main|M35 2 1/2-ton cargo truck}}
The standard post-war {{frac|2|1|2}}-ton truck M35 was manufactured by REO, [[Kaiser Motors#Vehicles|Kaiser-Jeep]], [[Curtiss-Wright#Post.E2.80.93World War II|Curtis-Wright]], Studebaker, [[Studebaker-Packard Corporation|Studebaker-Packard]], [[AM General]], and [[Bombardier Inc.|Bombardier]] (Canada) from 1950 until the late 1980s, with remanufacture extending into FY1999. The M35 has had the widest range of bodies of any US truck.{{citation needed|date=July 2018}} The cab design itself became the military standard, also used by 5 and 10-ton trucks. First built with a gasoline engine, in 1964 the multi-fuel became standard. In 1991 existing M35s began to be upgraded with diesel engines and automatic transmissions. Canadian trucks had automatic transmissions as built.{{sfnp|Crismon|2001|pp=338-345}}{{sfnp|Doyle|2003|pp=127-155}}{{sfnp|TM 9-2320-361-10|1993}}
===GMC M135===
[[File:M135 Meskens crop 2.jpg|thumb|GMC M211]]
An evolution from their widely successful CCKW, General Motors' successor "Deuce and a Half" {{frac|2|1|2}}-ton M135 was classed as a substitute standard in the US Army after the REO M35 was standardized, and thus was employed in much smaller numbers, but the M135 was also widely used by the [[Canadian Army]].
The six-wheel M135 cargo / personnel truck featured a 180-inch wheelbase with a single-wheel rear tandem and 11:00x20 size tires, necessitating a wheel well in the cargo bed for clearance. The M211 was identical except it had a dual-wheel tandem and smaller 9:00x20 tires. Other dual tandem versions produced were the M217 fuel tanker, M220 shop van, and M222 water tanker, plus the shorter M215 dump truck and M221 tractor with a 168-inch wheelbase. The M135 was the only {{frac|2|1|2}}-ton truck of the era designed with an automatic transmission. The transmission had 4 speeds and 2 ranges, with a single range transfer case.{{sfnp|Crismon|2001|pp=336-337}}{{sfnp|Doyle|2003|p=156-160}}{{sfnp|TM 9-819|1951}}
==Bodies==
===Cab===
All of the 1940 designs had commercial type closed cabs with minor modifications. Variants had an open passenger roof so a ring for a [[M2 Browning|.50 caliber machine gun]] could be mounted, during World War II approximately one in four trucks had a ring. In 1942, to simplify production and reduce shipping height, all manufacturers began to use military style open cabs. Studebaker returned to closed cabs after only 10,000 open cabs were built because the major user USSR preferred closed cabs. The post-war M35 and M135 were designed with open cabs and half-doors. Most military cabs could mount a machine gun ring.  The M35 and M135 had removable hard tops available.{{sfnp|Doyle|2003|pp=110, 122, 127, 158}}{{sfnp|TM 9-500|1953|pp=21-83 to 21-90}}{{sfnp|TM 9-2800|1947|pp=279-281}}
[[File:M35A2,3 cargo.tif|thumb|M35 Cargo Truck]]
===Cargo trucks===
[[File:M342A2,3 dump.tif|thumb|M342 Dump Truck]]
All series had a cargo model with a {{convert|12|ft|m|2|abbr=on}} body on a long wheelbase. The 1940 designs had a {{convert|9|ft|m|2|abbr=on}} prime mover type body on a short wheelbase, the M35 series had a {{convert|17|ft|5|in|m|2|abbr=on}} body on a longer wheelbase (178&nbsp;in).
All models had removable sideboards and overhead bows for a tarpaulin over the cargo area. All except the extra-long wheelbase M36 (214&nbsp;in) had folding troop seats in the sideboards.
Late in World War II, to conserve steel, cargo bodies were made largely of wood, postwar the M35 and M135 series returned to steel.{{sfnp|Ware|2014|pp=236, 238-329}}{{sfnp|Doyle|2003}}{{sfnp|TM 9-500|1953|pp=6-10}}{{sfnp|TM 9-2800|1947|pp=266, 273-275}}
===Dump trucks===
All series had [[dump trucks]] on both short wheelbase (166&nbsp;in) and long (178&nbsp;in). The US6 also had side-dump trucks. The cab stone-shield could be removed on most to lower shipping height. They could be equipped with overhead bows, tarpaulin, and troop seats.{{sfnp|Crismon|1995|pp=185}}{{sfnp|Doyle|2003|pp=111-112,124-125,132-134, 158}}{{sfnp|TM 9-500|1953|pp=21-69, 21-74}}{{sfnp|TM 9-2800|1947|pp=271, 272}}
{{clear}}
[[File:M275A2,3 trac.tif|thumb|M275 Tractor Truck]]
===Semi-tractor trucks===
The M-6H-6, M211, and M35 series had a [[Tractor unit|semi-tractor]] on a short wheelbase (166&nbsp;in), the M35 series also had a long tractor (178&nbsp;in). GMC made a few tractors based on the CCKW 352<ref name="GMC_CCKW_Tractor">{{cite web |url=http://www.surfacezero.com/g503/showphoto.php?photo=81664&title=gmc-cckw-tractor&cat=2222 |title=GMC CCKW Tractor at The G503 Album|access-date=14 May 2018}}</ref> during World War II. Studebaker never built a 6x6 tractor but built a 6x4 model.
Semi-tractor/trailers have limited off-road performance, and are not rated for full off-road use. The M35 and M211 series fifth wheel load rating was {{convert|12,000|lb|abbr=on}} on road and {{convert|7,000|lb|abbr=on}} off-road. A {{convert|36,000|lb|abbr=on}} trailer could be towed on road and a {{convert|17,000|lb|abbr=on}} trailer off-road.{{sfnp|Crismon|1995|pp=185}}{{sfnp|Doyle|2003|pp=124, 130-131, 159}}{{sfnp|TM 9-807|1943|pp=11-12}}{{sfnp|TM 9-500|1953|pp=21-90 to 21-95}}
{{clear}}
[[File:M49A2,3 tank.tif|thumb|M49 Tank Truck]]
===Tank trucks===
All series had fuel and/or water [[Tank truck|tank]] versions on long wheelbases. Capacities were {{convert|750|usgal|L|abbr=on}} to {{convert|1200|usgal|L|abbr=on}} in 2 or 3 compartments, depending on the series and whether carrying gasoline, water, or other liquid. Most had pumps and some had heaters. Most World War II units could be fitted with bows and a tarpaulin to camouflage themselves as common cargo trucks.{{sfnp|TM 9-500|1953|pp=21-83 to 21-90}}{{sfnp|TM 9-2800|1947|pp=279-281}}{{sfnp|Doyle|2003|pp=111-115, 124, 134, 137, 158-160}}
{{clear}}
===Van trucks===
[[File:M185A2,3. van.tif|thumb|M109 Van Truck]]
The CCKW, M35, and M135 had a {{convert|12|ft|m|2|abbr=on}} van model on a long wheelbase. These could be equipped for many different roles. The M35 also had a {{convert|17|ft|m|2|abbr=on}} model with slide out sections on both sides. Van bodies were used for medical, communication, machine, repair, and other shops. They could have different sizes, window arrangements, and other special equipment. "Expansible" vans are used for communication equipment.{{sfnp|Doyle|2003|pp=117, 138-142, 159}}{{sfnp|TM 9-500|1953|pp=21-113 to 21-117}}
===Chassis-cabs===
The GMC CCKW and M35 series had chassis-cabs in different wheelbases for specialty bodies. Maintenance, engineer, water purification, pole-setting, air compressors, fire fighting, and other equipment were also mounted on chassis cabs.{{sfnp|Doyle|2003|pp=114-117, 142-153}}{{sfnp|TM 9-500|1953|pp=21-19, 21-30}}{{sfnp|TM 9-2800|1947|pp=218, 267-268}}{{sfnp|TM 9-2800|1953|pp=225, 235,236, 239, 240}}
{{break}}
==See also==
*[[Einheits-PKW_der_Wehrmacht#Leichter geländegängiger LKW|Einheits-LKW der Wehrmacht]] – Nazi Germany's standardized 2½-ton, 6x6 truck for WW II, of which under 15,000 were made
==Footnotes==
{{reflist|group=nb|20em}}
==Reference notes==
{{reflist|20em}}
==General references==
*{{cite book|url=https://books.google.com/books?id=Og0KAQAAMAAJ|last=Crismon|first=Frederick W.|title=International Trucks|year=1995|publisher=Motorbooks International| isbn=978-0-7603-0069-5}}
*{{cite book|last=Crismon|first=Fred W|title=US Military Wheeled Vehicles |edition=3|year=2001|publisher=Victory WW2|isbn=978-0-9700567-1-9|pages=356–362}}
*{{cite book|url=https://books.google.com/books?id=52WIEG-1TjgC&pg=PA36|last=Doyle|first=David|title=Standard Catalog of U.S. Military Vehicles|edition=2|year=2003|publisher=Krause|isbn=978-0-87349-508-0|pages=105–160|access-date=2018-04-26|archive-url=https://web.archive.org/web/20180115001518/https://books.google.nl/books?id=52WIEG-1TjgC&pg=PA36|archive-date=2018-01-15|url-status=dead}}
*{{cite book|last=Hyde|first=Charles K.|title=Images from the Arsenal of Democracy|year=2014 |publisher=Wayne State Univ.|isbn=978-0-8143-3982-4|pages=203–207}}
*{{cite book|last=Ware|first=Pat|title=The Illustrated Guide to Military Vehicles|year=2014|publisher=Anness|isbn=978-1-78214-192-1|pages=238–239}}
*{{cite book|url=http://www.radionerds.com/index.php/File:TM_9-500.pdf|title=TM 9-500 Data Sheets for Ordnance Type Material| publisher=US Dept. of the Army|date=1962|pages=Sec. 21|access-date=23 Apr 2018|ref={{harvid|TM 9-500|1953}}}}
*{{cite book|url=http://radionerds.com/images/8/8a/TM-9-801_GMC-CCKW-352-353.pdf|title=TM 9-801 Truck, 2 1/2-ton 6x6 GMC CCKW-352 & 353|publisher=US War Dept.|date=1944|access-date=27 Sep 2019|pages=13–14, 35–40|ref={{harvid|TM 9-801|1944}}}}
*{{cite book|url=http://radionerds.com/images/6/67/TM_9-807_STUDEBAKER.pdf|title=TM 9-807 2 1/2 ton 6x6 Truck and 2 1/2 to 5-ton 6x4 Truck (Studebaker Models US6 and US6x4)|publisher=US War Dept.|date=1943|access-date=27 Sep 2019  |ref={{harvid|TM 9-807|1943}}}}
*{{cite book|url=http://radionerds.com/images/9/92/TM_9-819_M34.pdf|title=TM 9-819 2 1/2 ton 6x6 Cargo truck M34 (and others)|publisher=US Dept. of the Army|date=1952|access-date=27 Sep 2019}}
*{{cite book|url=http://radionerds.com/images/9/9b/TM_9-819A_2%2C5-TON_6X6_TRUCK_M135.pdf|title=TM 9-819A 2 1/2-ton 6x6 truck M135|publisher=US Dept. of the Army|date=1951|access-date=27 Sep 2019 |ref={{harvid|TM 9-819|1951}}}}
*{{cite book|url=https://www.liberatedmanuals.com/TM-9-2320-209-10-1.pdf|title=TM 9-2320-209-10-1 Operation, Installation, and Reference Data Operator Level 2 1/2-ton, 6x6, M44A1 and M44A2 Series Trucks (Multifuel) |date=1989|publisher=US Dept. of the Army|access-date=15 Jul 2019}}
*{{cite book|url=https://www.nsncenter.com/Files/library/TM/M35/TM-9-2320-361-10/TM-9-2320-361-10.pdf|title=TM 9-2320-361-10 Operator's Manual for 2 1/2-ton, 6x6, M44A2 Series Trucks (Multifuel)|date=1988|publisher=US Dept. of the Army|access-date=15 Jul 2019|ref={{harvid|TM 9-2320-361-10|1993}}|archive-date=17 June 2019|archive-url=https://web.archive.org/web/20190617165105/https://www.nsncenter.com/Files/library/TM/M35/TM-9-2320-361-10/TM-9-2320-361-10.pdf|url-status=dead}}
*{{cite book|url=https://sd3624203692.files.wordpress.com/2019/06/tm9-2800-veh-47.pdf|title=TM 9-2800 Military Vehicles|publisher=US Dept. of the Army|year=1947|access-date=15 Jul 2019 |ref={{harvid|TM 9-2800|1947}}}}
*{{cite book|url=https://sd3624203692.files.wordpress.com/2019/06/tm9-2800-veh-53.pdf|title=TM 9-2800 Military Vehicles| publisher=US Depts. of the Army|date=1953|pages=222–242|access-date=24 Apr 2018|ref={{harvid|TM 9-2800|1953}}}}
==External links==
*[http://www.jatonkam35s.com/index.htm  US Army Technical Manuals at Jatonkam]
*[https://www.liberatedmanuals.com  US Army Technical Manuals at Liberated Manuals.com]
*[https://www.nsnlookup.com/equipment-intelligence/land/m35  US Army Technical Manuals at NSN Lookup]{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}
{{DEFAULTSORT:2-ton 6x6 truck}}
[[Category:Military trucks of the United States]]
[[Category:World War II vehicles of the United States]]