(first posted 2/7/2014. It’s Memorial Day in the US, and in honor of all the men and women who gave their lives in service to this country, let’s take another ride in one of the most significant tools of WWII)
Maybe you found your way to CC because you were sick of all those infantile “We Drive The World’s Fastest Cars” 200+ mph shoot-outs or such on endless glossy magazine covers. No, we’re strictly grown ups here, and confine ourselves to erudite discussions of historical minutia and debating alternative business plans that would undoubtedly have catapulted Packard into being the world’s largest luxury car manufacturer today. But we all have our moments of weakness, as when I was confronted with this offer: “Hey Paul, you want to take a ride in my GMC CCKW, and see what she’ll do, wide open?” Did you have to ask?
When I need certain heavy-duty mechanical jobs done, like the clutch replaced in my truck, I head to Jeff’s Garage. But since that happens very rarely, I sometimes just drop in and see what his latest toy is. Jeff’s taste mirrors mine: older original vehicles with plenty of patina and used regularly; for a long time, his daily driver was his 1936 Plymouth, which he even let me drive (CC here).
Jeff’s latest ride is a wee bit younger than that, but decidedly gnarlier. And since he welcomes any opportunity to take it out for a spin, he invited me along. Actually, he offered to let me drive it too, but I decided that making a video of him working the old Jimmy through the gears up to top speed might be be easier on the seventy-year-old non-synchronized gears, as well as his ears. Although I suspect its crash-box transmission has seen some tough grinds in its long life.
image credit: wwiivehicles.com
Of the three WWII 2.5 ton 6×6 trucks (GMC, Studebaker, International), the GMC “Jimmy” was built in the greatest numbers by far, undoubtedly due to GM’s huge production capacity. Over half a million were built for the Army and the Lend-Lease program, and they were most famously employed in the Red Ball Express, the vast supply line that served the advancing Allied troops marching east after the Normandy invasion. At its peak, almost 6,000 vehicles were on that road daily, from the port at Antwerp to the front lines. The Jimmy acquitted itself superbly, cementing its place in history.
Initially, all CCKWs had closed cabs, as used on civilian GMC trucks of the time. But presumably to save on precious steel, later version also came in a simple open cab, with folding windshield and canvas top. Even in the bed, wood eventually substituted steel. These trucks came in two wheelbase lengths (145″, 164″) and were used in a wide range of duties, with an equally wide range of beds.
Jeff’s truck is an open-cab version that has had a closed-cab kit attached. The dump bed is not original; this truck worked for many years as a gravel hauler for a back-woods logging operation. Jeff plans to put an open bed on the back, something like it would likely have had originally.
The attachment bolts for the upper half of the cab are clearly visible. Nice “opera window” on the back, although that hardly makes this a Brougham. Every square inch of this truck is solid steel and patina, with a dash of glass and rubber thrown in for good measure.
Let’s check out the rest of this truck before we hop in. One of the most obvious things is that it’s only got single wheels on the back. That’s because the prior owners put larger size tires on it (9.00×20), instead of the original 7.50x20s. Jeff has a lead on some original sized rubber, and already has someone to take the dump bed and put it to use on an old Ford (not mine!). But there’s plenty of times I’d wished I had a dump truck like this.
The other thing that’s instantly noticeable is the rear axle differential housing, which has its main ring gear oriented longitudinal, like vintage Fords. CCKWs came with two types of rear axles; Timken split axles (which is what these are) or the GMC banjo type axles, that look like typical modern axles and were considered the stronger of the two.
But that’s not nearly as different from more modern trucks than how the drive to the two rear axles is arranged. Instead of one drive shaft feeding both axles, there’s two; with the one heading to the rear-most axle having an intermediate rest stop on top of its more forward companion.
Here’s the rear output of the transfer case, with a parking brake on the shaft on the left, which feeds the rear-most axle. The other one is a bit below on the right. I wonder if there’s some intrinsic advantage, like redundancy if one drive shaft or axle craps out? These trucks were known to be nigh-near un-killable.
For all you lovers of undercarriages, shafts and universal joints, here’s that transfer case from the front.
And the front axle, of course; which appears to have a reinforcing bar.
Before we fire her up, let’s pay our respects to that winch. I wonder what stories it could unwind for us.
There’s the legendary GMC 270 CID (4416 cc) OHV six, rated at 91.5 hp in this application. The GMC six was built in two main versions, a low deck (236 and 248 CID), commonly used in pickups and light trucks from 1939 up to about 1960. The raised deck block came in 256. 270 and 302 CID versions; the 302 being particularly desirable due its phenomenal torque.
That’s not to say these Jimmys couldn’t make gobs of horsepower either; they were one of the most commonly used engines in hot rods, dirt track and Bonneville racers, and even sports cars with six Amal carbs , as well as six swept exhaust pipes thanks to an aftermarket cylinder head. Their performance heyday overlapped with the Ford flathead V8 — which it was quite capable of spanking too — from the late 30s up to about 1955 or so, when OHV V8s became plentiful, especially the Chevy. Can you imagine what this one sounds like at full chat?
Here’s a quick warm-up, literally, to our main drive, as Jeff starts up the Jimmy and pulls forward a bit. Jeff has a lead on a 302, which he’s thinking of rebuilding and dropping into his CCKW. The 302, in conjunction with the four-speed Hydramatic (with two ranges), was used in the CCKW’s successor, the M135.
Now let’s hop in and get ready for our drive. The cab is a very spartan affair, not surprisingly, and mighty cozy too.
Instrumentation is complete, in terms of the usual vital statistics.
The CCKW has a five speed manual, with direct gear being fourth, and an overdrive fifth. The two-speed transfer case gives a wide range of speeds based on the maximum engine speed of 2750 rpm, from a wall-climbing 2 mph to 45. As the chart says, that’s based on it being equipped with the 7.50×20 tires, and this one has oversize 9.00x20s, so the speeds in gears will actually be a bit higher; 2.3 mph in low-low?
The shift pattern is a bit hard to make out on the plate, but it’s not exactly what we’re used to in modern cars. Second (typical starting gear) is at the top left; then down for third; then over and down for fourth, then straight up for fifth. Reverse is on the far right top, and first is below that.
We drove a couple of miles out West 18th to blow out its cobwebs, and started rolling video just as Jeff turned the Jimmy around to head back into town. Jeff said that the tired 270 six would probably benefit from a good tune-up or even a re-build, but it chuffs right along. The speedometer is way out of whack, at least in part due to the larger tires. I’m guessing we managed to get up to around 45 or so; it certainly felt at least that fast or more, due to the noise. The ride is of course stiff and bouncy, but not quite as bad as I might have expected. The CCKW’s 2.5 ton load rating was very conservative, and it was commonly doubled in real world (war) use.
And what is the very first car we encounter and follow as we get back to Curbsidelandia? A Mercedes W116 S-Class from the seventies. We tried to catch it, but I’m afraid the Jimmy wasn’t quite up to it, even if the Benz was a diesel 300SD. If the Jimmy had a warmed-over 302 with five carbs, it would have been a different story.
Jeff is in love with his new big toy, which means some of his other projects are languishing. But that’s how it is with serial automotive monogamists, and this one is certainly lovable as well as driveable. And I’ve been invited to retest it when the 302 goes in. It should blow right through fifty then.
Postscript: Unfortunately Jeff passed away a few years back.
“Maybe you found your way to CC because you were sick of all those infantile “We Drive The World’s Fastest Cars” 200+ mph shoot-outs or such on endless glossy magazine covers.”
That is EXACTLY why and don’t ever stop.
Amen, brother. At least here there are real cars, not rich dweeb toys.
Keep up the good work Paul, I too have no use for those “world’s fastest cars” shoot-outs (that means you Car & Driver) and I find your posting on vehicles like the 1944 GMC 6 x 6 so interesting. Maybe a comparison test between a GMC and a Studebaker would be wild!
This is a great article and I enjoyed reading it. I also enjoyed the two videos. I would think that an open cabbed Jimmy would not be so ideal in a war zone. I noticed Jeff clipped the yellow line when moving into the turning lane and that is an annoying thing that Oregonians (or recent Oregon transplants) do that I am still getting used to. The locals where I grew up rarely prematurely enter the turning lane even blocking a lane of traffic in the process so when I do the same I have almost caused several accidents because of people illegally crossing the yellow line sometimes up to half a block early and I do not think of looking over my shoulder when following the yellow line. Course there are numerous spots where the left turn and right turn lanes could be made longer.
I will admit that I often do California Stops in a safe manner, speed a bit, and usually coast to redlights so I do not have to stop so do not think I am some saintly figure bashing all the sinners.
So, what has become of the 36 Plymouth, I still like reading that article.
Actually the open cab version is more desirable in combat as it increases visibility for the driver. It is also common in these situations to fold the windshield down flat and then cover it so glare doesn’t give your position away. I have a lot of seat time in the M35 6X6 that replaced this one, and 45-50 MPH is about as fast as I would want to drive one. They are certainly capable of going faster but those “universal” type tires start to get a little squirrelly at speed. Kudos to your friend for keeping this beast alive and actually driving it.
Alice Springs to Darwin at 35mph these things did in Aussie on the bitumen one lane laden trucks got the tar road returning convoys pulled over onto the gravel.
There were still many of the 6x6s in govt service in the early 70s in NZ used for tower line construction in rough country they were disposed of due to ancillary parts supply problems and replaced with 6×6 D Fords which had to be towed everywhere, the wartime Jimmys were designed to be able to follow a tank to provide infantry support they will go anywhere literally a tank could go.
My uncles family used a Studebaker 6×6 for logging up till they lost use of native bush in the late 80s goood trucks.
It was armored half-tracks like the M2, M3, & Hanomag that were designed to be able to follow tanks; unarmored trucks like this were more rear echelon. However, because some CCKWs were built with machine-gun rings, planners assumed they might be used in combat zones.
Actually the open cab version is more desirable in combat as it increases visibility for the driver.
iirc, my Dad told me that vehicles were required to have the tops folded in combat areas. Being in the artillery, he rode across France and Germany in the back of a deuce and a half. They often didn’t bother looking for a road in the direction they wanted to go, but just took off across the fields. Many times his truck was in mud up to it’s hubs, and kept going.
Only close call he had in one was passing a couple guys manhandling a 37mm gun. The mine detector crew that cleared the road just put the mines on the shoulder of the road and the 37mm crew ran their gun over one. The gun, and the guys, were blown to bits, with one of the wheels of the gun putting a major dent in the side of Dad’s truck.
While the open cab has many benefits, the main driver behind the design was shipping efficiency.
With the windshield down and a foldable roof, the total height was no greater than the cargo bed. This allowed shipping in.a greater variety of vessel holds and speeded loading and unloading. Closed cabs could be added in-theater when needed.
Even after WWII, the design practice continued for many years as it allowed for better loading in various aircraft frames.
It’s in the shop, taking a rest.
Thanks for the “ride”. That engine really sounds smooth and solid.
Personally I’d keep it or if necessary one like it.
SWEET ! .
That 2nd right knob was the original headlight switch , the button prevents Beetle Baily from switching on the headlights in a Black Out Area .
I grew up in Rural New England and that Winter Cab is likely worth more than the whole truck .
These were indeed fantastic trucks and yes , the 270 sounds great but clearly isn’t working very hard there .
I still see these old Jimmy’s working here there , few are are as clean and unmolested as this one though .
Be nice to find a Troop Carrier Bed and restore it .
Light switch lockout; that explains it. Thanks. I’ll fix it.
_Headlight_ lockout ~ the first click switched on the park and tail lights.
When I were a lad in New Hampshire , we had a beastly 1952 Studebaker Duece with a big old V -plow on it for snow plowing the back roads .
How do I go about adding an avatar here ? . I see no hyperlinks , nuttin’ .
Last night my buddy was talking to me about his ’37 Chevy Business Coupe , in 1955 or so he stuffed a GMC 270 with triple carbies in it……..
That unusual shift pattern had advantages if you get bogged in mud the 1st reverse shift is straighthru so you can rock the vehicle free Ferguson tractors use a similar pattern.
A lot of smaller tractors do; at least, older ones. We recently (within the past year) obtained a JD 1020 and a 1520 as runabout tractors, for moving hay racks and wagons and things, and also because they’re just such fun little tractors to “putter around” with. Both tractors have two shift levers, and the shift patterns are
P – down – II (high range) – across – R – up – I (low range)
and 1/5 – down – 2/6 – across – 3/7 – up – 4/8.
The ONLY thing intuitive at all about the first shifter is that going from R to I (like when backing up to a wagon, having someone else hitch up, and then going forward) only requires the lever to go forward. But more than once when in 2/6 I’ve forgot about 3/7 and skipped over it up to 4/8. That’s a rush going down a winding sloped driveway .
Plus the PTO isn’t live, so to engage it you have to push the clutch all the way forward (leg fully extended with your toes barely touching the pedal) and throw an unmarked switch on the side of the diff.
When Field Marshal Bernard Montgomery was asked “What was the most important weapon of WWII?” he replied, “the GMC 6X6 truck.”
Not only was it a truck, it was a system. For example, its braking system integrated into every US and later British artillery system. It could tow a 155 mm “Long Tom” gun at 45 mph on good roads. The Germans towed their similar weapon with 12 (and later 8) horse teams at a good 3 mph. It was a brilliant design.
I thought Monty would’ve praised the CMP instead (built by Chevy & Ford’s Canadian divisions). But maybe that was because his vehicles in N. Africa came direct from the US, not the British supply chain.
He got the Sherman before US armored divisions did.
45mph in this though must feel like a hundred…
I remember a guy I knew that drove the much much much newer versions of these in the Army in the 90’s, the M35 I believe, and he would tell me stories of “topping them out” at 55 or 60, faster than the WWII era trucks, but he said it felt like going 200mph due to the noise and the rough ride.
BTW, is that a tasty boat tail Riv being guarded by this Deuce?
Yes – 45mph was plenty fast for a 1940’s military truck.
Thanks for posting this, Paul! I just geeked out on hi torque military badassery! This thing may look gnarly but it howls along like a well oiled machine. Ill bet even riding along was a blast.
Old military iron seems common in these parts. When I lived down near Roseburg, there was a local who came into the dealership I worked at (house of Ma Mopar) who had at least 3 WWII era Dodges. A pickup, a command car and I think an open top model too. He was a bit eccentric, but a cool dude just the same.
Anyone else notice that pristine IHC Scout at 3:02?
My father had a 1940 GMC that must have been a very early version of this. It had the standard civilian cab and instrument panel but the military front sheet metal. It had the little “black-out” lights that if they were on, maybe someone could see the truck coming. He used it as a short logger; it hauled lots of skinny second-growth Douglas fir logs off wooded lots in south King County and neighboring areas of Pierce County.
It sounded enough like the one you rode in to bring back memories.
The scrap yard I frequent had a very rough-sounding Deuce-and-a-half based magnet crane up until around 2008-09 or so when scrap prices shot through the roof. New Komatsu material handlers showed up that year and the Deuce disappeared.
Thanks for the tour and a great ride-along. I loved the mechanical symphony of olf trucks like this. Funny thing, from the vantage point inside this old WWII truck, when you zoomed in on that Mercedes, my immediate reaction was to either start shooting or take cover. 🙂 Too many old war movies rattling around in my head, I guess.
Thanks for this post Paul, and for truck week everyone. I have been silently reading along and enjoying the posts and comments.
The Deuce and a Half is my favorite old workhorse. When my dad was in the Army and I was little, I was treated to some seat time in the 1970’s variant of the 6×6 truck. It definitely left an impression on me. Even into the 1990’s, when I was working as a mechanic, you’d still see one of these old soldiers still working as an off road supply truck, or a drill rig here in Pennsylvania.
I also like the ride along videos of these old trucks with a veteran driver getting gears. Good stuff.
This is outstanding! An awesome old truck and the video truly enhances the experience.
Lots of US Army trucks were “civilized” after WW2 to rebuild the country. A 6×6 is of course an excellent base for a dump truck, like this one. That’s basically how off-road specialists Ginaf and Terberg started. A diesel engine was swapped in as standard procedure. Perkins for example, later on DAF diesels. This was done way into the sixties, Reo military trucks quickly became the favorite conversion-truck for Ginaf and Terberg.
Kickback can break thumbs!! Thumbs stay on the OUTSIE OF THE STEERING WHEEL!!
Paul, you have great talent for writing and an eye for the right subject. Jeff is a special person for many reasons including his love for vintage vehicles. I think of him as living in a different era than the one we’re in, and his choice of vehicles proves it! Thanks again for an entertaining read.
I saw one of these in Tigard today going down a residential street, but without chains. Probably was one of the more planted vehicles on the road.
Was in the military from the early sixties till the early eighties. I was certainly no mechanic but a vehicle that sure looked like this was still used by the Marines. Guess it was the successor you mentioned. Good article and good find.
As far as hot rodding goes, I think I started reading Hot Rod Magazine by 1950-52. It seemed like any rodded GM product had the big GMC six for a spell. That slowed a little in 49 but the Olds and Caddie V8s were expensive and chev didn’t come around till 55. They really became popular with the 283 in 57 and the big sixes weren’t seen so much after that. I think the last one I saw was about 5 years ago and it wasin a mid 30s coupe with a turbo. I’m surprised the torque didn’t flip it over. One of my favorite engines. Would love to have one in my 57.
Used to see these and frod/Chevrolet Blitz trucks working in New Guinea in the 60s & early ’70s.
And Isuzu built a near copy- down to the split axle design.
BTW, the “reinforcing bar” in the front axle pic is the steering tie rod.
I used to drive these trucks in the early 50’s mainly as tip trucks or tar sprayers and we didn’t stuff about with 2 1/2 ton payloads we carted 12-14tons and in the logging industry with a tandem jinker they used to have an all up weight of just under 40tons.the motors used to last about 3 weeks and you yanks left plenty of spares here so it cheap to keep on reconditioning them.
I have the same truck (a 1943, mine has the closed cab and the banjo type axles) I got it a couple of years ago for $1000, it wasn’t running when I got it but I soon fixed that. About a year ago a friend of mine sold me a millitary 302 from a 1953 gmc, I am working on putting it in sometime soon. He also sold me 11 9.00×20 that I will put on also sine the ones that it has on it are not orginal and are in very bad shape.
A great website you should check out if you haven’t already is (the gmc cckw.com) (don’t know how to post a link to it)
Somewhere I have a video of taking it ‘through its passes’ after we got it started, it’s amazing the articulation the back axles have from each other.
Thanks for a great article on this vintage military machine on Memorial Day. My dad drove one of these in WWII and spoke highly of it’s reliability and capabilities. He related to me that he perfected the art of “double clutching” one of these during training exercises in the mountains of the SW United States before being deployed to Europe. Brings back good memories from my childhood.
Missed this driving impression the first time. Very cool.
Dad’s workhorse was the C47 (DC3).
Pathfinder group 305th, 82nd Airborne, Company 1, 116th Infantry Regiment from Nov.11th 1942 to Oct 19,1945.
Parachuted into Italy on D Day. Parachuted on at age 90 in 2013, to join Mom who passed age 81 in 2010. Their ashes are together now at Willamette National Cemetery.
Thanks to all who served and those who died protecting our country.
I don’t remember this one from 2014–thanks for reposting. The video was a treat, and I’ve gotta believe that you widened the eyes of at least a few of the oncoming drivers–including the F150/Ram/Silverado types.
You and the other CC contributors write snazzy lead paragraphs–but the story always lives up to opening.
If you’ve got your Time Machine working, Paul–and a bit of ready cash–here’s a 1947 ad to check out (BTW, could anyone estimate that percentage of these used overseas (WWII) that got brought back to the States?):
I don’t know for sure but I would be surprised if very many of them were returned back to the states after WWII service. Even the ones that weren’t worn out would have been left in place to be sold as surplus as it would have cost more to ship them home than they were worth. When the war in Europe ended the major priority was returning people back to the U.S., in many cases to be retrained for the expected invasion of Japan. When the Pacific war ended the military was rapidly downsized and there would have been plenty of new equipment available for the remaining troops. It wasn’t only wheeled vehicles that were basically abandoned or sold for pennies on the dollar; entire airfields of planes were either sold for scrap or left to rot. Even complete ocean going ships were sold off as surplus for what amounted to token sums.
Yes. Huge numbers of vehicles were abandoned in France, etc. and Europe in general. The GI’s wanted to get home! My Dad remarked that we shot those Frenchmen who tried to break in these truck parks, and then abandoned them…; gave them away for nothing.
My Dad said everyone wanted to go home!
What a shame. True, it would cost more to ship them back to the USA than they were worth $$$. What a shame.
Dad bought several ex-military vehicles for his business immediately after the war; they were the only machines available for several years. He had a 4X4 command car for a truck, a 4X4 1 ton winch truck (or 1&1/2 ton), and a 6X6 GMC to pull the drilling rigs and heavy trailers.
In the 1950’s, I (ten or eleven years old) learned to drive by sneaking out of the house (weekends & holidays) when my dad was taking his afternoon nap. It was grand fun! Of course, he found out. And laughed, surprised at my mechanical ability.
Sadly the old trucks were sent to the salvage yards: the 6×6 in the 1960’s and the 4×4 in the 1990’s.
The war time truck that was in the highest regard in the USSR – by almost infinitely wide margin – was the Studebaker US6.
They were legendary for their strength, reliability and for being very humane to their drivers (as opposed to antiquated Ford-AA and Autocar Dispatch SD – based GAZ and ZIS).
The most of those that were not returned under the lend-lease agreement, stayed in service well into the 60’s, with some surviving until early 80’s.
The major suppliers of 2.5 ton 6X6 trucks during WWII were GMC, International, and Studebaker, with a small number of Studebaker versions assembled by REO. In order to facilitate parts supplies and service in the field, it was decided (largely on production capacity) to supply the U.S. Army with GMC’s, the U.S. Navy and Marine Corps. with Internationals, and lend-lease the Studebakers to the Soviets. There were exceptions, but generally speaking this was how the trucks were distributed.
My first USAF posting was an AC&W radar site outside of Bartlesville, OK. We sponsored an Explorer Scouts post, electronics-themed of course, but it was mostly hanging out with some good kids not quite our age. There was a camp weekend on Grand Lake coming up, and it was decided that we’d haul camping gear and our electronics exhibit trailer behind a 6×6 borrowed from whatever base was closest. If I was going I had to have my military-vehicle license upgraded to cover driving that thing in case everyone else became disabled, but the only available vehicle in that category was our dump truck. So the motor-pool sergeant pulled that out to the road going down our hill, put me in the driver’s seat and showed me the shift pattern and which gears to use for road work. So I started it, brake off, went grinding down the hill at fifteen or so mph. Thank heaven there was a big turnaround at the bottom, though I had to use reverse because it wasn’t that big, and then we went grinding back up the hill. I stopped, he signed whatever endorsement was required, he said, “Hope you don’t hafta drive that thing,” and I said, “Me too,” and that was that.
I did ride in the cab going however many ungodly long miles it was to Grand Lake, praying fervently for the driver’s continued good health all the way. After a couple of fun days we were leaving, and one of the scouts was begging to ride in the 6×6. Another scout’s mom kindly offered me a ride back in their station wagon so the kid could have his Big Truck Ride, which I graciously allowed him.
One of our respondents said he figures that 45 mph in one of these must feel really fast. Sir, you are wrong about that. 45 mph has never felt slower than that crawl across eastern Oklahoma …
Though from what I’ve read Mack had an interaxle differential “power divider” available since at least 1931, it doesn’t appear to be common until after WWII. Without a power-divider, the two rear axles are locked together, which makes turning a bit more of a hassle and contributes to tire wear when running on paved surfaces – and you better have matched tires on the rear axle. For unpaved surfaces it’s a surer-footed way to go, no inter-axle differential to break, and if one of the axle differentials goes out, well just pull the axle shafts and disconnect the separate driveshaft. The CCKW transfer case does not have a front-rear differential either, so the front axle is only engaged off-highway or in other extreme conditions.
Very sad to read that about Jeff, going by the video he was too young.
Army training film–basic inspection, shifting, etc.: https://www.youtube.com/watch?v=JkmP46pSbz0
Driving in challenging situations: https://www.youtube.com/watch?v=QZu5K8cJvVI