The Mercedes-Benz Unimog is a legendary off-roader and for many, the perfect base for an expedition vehicle. Sadly, Americans miss out on being able to buy these beasts new. One firm wants to change that. Couch Off-Road Engineering takes old Unimogs, gives them modern power and a highway-capable top speed, and will sell them to you as about the closest thing you’ll get to a new old Unimog in America.
Expedition trucks were a common sight at Overland Expo West. I love these gargantuan machines. The idea behind an expedition truck is a vehicle that can survive the toughest terrain and some of the harshest environments as you explore the world. You’ll see expedition trucks built on the backs of vehicles like a Ford F-550 Super Duty or a Chevrolet Silverado 6500HD.
For cabover-style designs, you might see expedition vehicles built on an Isuzu NPR or a Kenworth K370. However, one overlanding legend remains out of reach for so many of these builds. The last time Mercedes-Benz brought its Unimog to America was 2002, and it sold just 184 units between then and when the automaker called it quits in 2007. For most enthusiasts, that means Unimogs with modern power numbers are forbidden fruit.
That’s where Jay Couch comes in. To call Couch a Unimog enthusiast would be an understatement. As TFL Truck writes, Couch has over 50 Unimogs on his Denver, Colorado property. But Couch doesn’t just collect Unimogs. Through his enthusiasm, he’s perfected methods to turn old imported Unimogs into trucks with modern power numbers and highway-capable speeds while still retaining the trucks’ legendary off-road prowess and durability.
I spoke with Couch at Overland Expo and he explained to me that his Unimogs aren’t just old trucks imported over and given a kick of horsepower, but they’re rebuilt from top to bottom. In other words, a Couch Unimog is about the closest you’ll get to buying a new old Unimog without living in Europe.
Why The Unimog Is So Beloved
To understand why I’m so excited about this, and perhaps why some of you might be as well, let’s take a trip through time. Mercedes-Benz says that its fabled truck dates back 77 years to 1946. Mercedes—the car company, but I guess also me?—provides this fascinating bit of history:
Albert Friedrich is one of the Unimog vehicle’s founding fathers. Immediately after World War II the former head of Daimler-Benz aircraft engine production recognised the enormous need that small and mid-sized companies working in Germany’s agricultural sector had for tractors. In addition to off-road capabilities, there was great demand for a vehicle that was simple to convert for a range of very different tasks.
From 1946 a dedicated team headed by the engineers Albert Friedrich, Heinrich Rößler and Hans Zabel developed and tested the first prototypes for such a commercial vehicle on the premises of Erhard & Söhne. It was Hans Zabel who took the somewhat cumbersome project name “Universal-Motor-Gerät für Landwirtschaft” (Universally applicable motorised machine for agriculture) and created the succinct abbreviation “Unimog”.
If you’ve ever wondered what “Unimog” means, there’s your answer, and it’s about as German as it could be. There’s more. Mercedes says that by the end of the original Unimog’s development, the team engineered a four-wheel-drive beast with differential locks and portal axles. This made the Unimog practically unstoppable at assisting in agriculture but Mercedes also notes that the engineers achieved this while also making the truck still capable of driving 31 mph.
Comparing the Unimog to a tractor, another advantage the Unimog had was the ability to mount implements on all sides. Traditionally, Mercedes notes, a tractor could carry implements only on its rear. Toss in a Daimler-Benz OM 636 diesel, and the Unimog had the recipe to become a vehicular phenomenon.
In 1948 the Unimog was presented to a professional audience for the first time at the trade fair in Frankfurt organised by the German Agricultural society. There the response to the vehicle was very positive, not least due to its impressive driving characteristics both on the road and in difficult terrain, its easy operation and great versatility. That year, the Unimog also went into series production for the first time at the Boehringer factory in Göppingen which had already delivered cast parts for the prototypes.
The hallmark of the very first 70200 model series, of which around 600 vehicles were built, was the ox-head logo. Today there are still around 120 of those Boehringer Unimog – and many of them are still in operation.
From there, the Unimog has only expanded in its capability and roles. You’ll see Unimogs working roles in the military, in construction, at airport services, as snowplows, as cranes, as garbage trucks, and even as rally trucks running in the Dakar Rally. Of course, Unimogs also get turned into expedition vehicles.
Over the years, these trucks have earned their reputation for flexibility, durability, and incredible off-roading abilities.
Unfortunately, getting a Unimog in America is more difficult than it perhaps should be. Case Corporation, known for its construction equipment, imported Unimog U900s into America between 1975 and 1980. Then there was the Freightliner Unimog FLU419, which was made for the United States military between 1986 and 1991. Finally, Mercedes-Benz gave it another go in 2002 and sold Unimog U500s through Freightliner dealerships until 2007.
Only 184 of those last ones were sold before Mercedes-Benz pulled the plug, reportedly citing the truck’s inability to meet emissions requirements.
The Couch Nomadic Off-Road Adventure Design Unimog
Here’s where things get weird. The aforementioned Unimog U900s distributed by Case has a top speed of about 45 mph. The mil-spec Freightliner Unimog FLU419s go a touch faster at 50 mph. Of course, either would make for a miserable, if not illegally slow highway drive. Thankfully, the Unimog U500s are electronically limited to 70 mph, but again, just 184 of them are in the United States. So what do you do if you want a Unimog that’s both an off-road beast and highway capable?
Well, Jay Couch says you can pick up his N.O.R.A.D. (Nomadic Off-Road Adventure Design) Unimog. It’s faster and more powerful than the newer Unimog U500s while retaining the mechanical simplicity of older Unimogs. Couch has been in the business of repairing, customizing, and building Unimogs since 2002. When he isn’t spinning wrenches on German iron, he’s developing things like the T-Railer side-by-side trailer, which is so light that a Toyota RAV4 can safely tow it, and a side-by-side.
Couch’s Unimog builds start off by importing a Unimog that’s over 25 years old. The donor truck then gets rebuilt from top to bottom with improvements given along the way.
Couch says that these trucks come equipped with diesel inline sixes making around 150 HP or so. His team takes those engines and irons them out so that they make 320 HP and 800 lb-ft torque. Bolted to the engine is what Couch calls a 32-speed transmission.
See, the transmission has eight forward gears, which can be reversed. Then there’s the ultra-low speed working gear mode, plus crawler gears, both of which multiply the gear ratios. Add it up and you have 32 speeds. Couch says that the gearbox runs 380:1 to .7:1. His Unimogs will also go 80 mph, but cruising speeds are closer to between 65 mph and 75 mph.
David has written about the Unimog’s neat cogs before, so I’ll let him elaborate:
While I couldn’t confirm those Unimog 406/416 crawl ratio and top-speed figures with any official Mercedes documentation, I did find a brochure for the more modern Unimog U500. In it, I learned that the first gear ratio is 9.570:1, and that the gear can be used in “road gear” or “working gear” mode. In the latter mode, first gear is multiplied by a ratio of 5.757.
The “crawler” gear ratio—with the 5.575 “working gear” included—is 55.874, the rear axle ratio is 2.182, and the hub ratio (remember, this thing’s got portal axles), is 2.714.
So if you multiply that all out—first gear ratio (9.570) times crawler gear ratio (55.874—this includes the working gear) times axle ratio (2.182) and finally times hub ratio (2.714), you end up with a crawl ratio of almost 3,200.
This means the engine’s torque (700 lb-ft at 1,200 rpm) gets multiplied by that value, yielding a maximum of over 2 million lb-ft of grunt at the wheels.
I’m told that yes, the fact that you can run these gears in reverse means that you can drive one of these trucks 80 mph in reverse if you’re crazy enough. Apparently, Couch took one to 50 mph in reverse before backing down. He’s also taken the trucks to 80 mph in forward, but those speeds feel a bit unnatural for the off-road beast.
In terms of off-road gear, the Couch Unimogs mean business. Of course, the Unimog’s characteristic portal axles remain, as do the truck’s front and rear locking differentials. The trucks roll on 42-inch to 46-inch tires wrapped around beadlock wheels. Those are aired down and up using a central tire inflation system and Couch says that the trucks have 19 inches of ground clearance from the bottoms of the differentials.
Something that Couch’s team was excited to talk about was the fact that you get that healthy modern power, but without all of the electronics of today’s diesels. There are no fault codes to worry about or computers to die on you. Couch tells me it’s all mechanical, which should mean a long-lasting expedition vehicle.
Comfort is also a pretty big deal for Couch. These upgraded Unimogs sport auxiliary heat and a 16,500 BTU air-conditioner. That’s enough cooling power for a decent apartment, let alone a truck. Couch also worked to lower noise levels for a more enjoyable drive.
Another benefit that Couch touts are the fact that the frame and body are isolated. As Couch explains, when you mount a camper to a pickup frame, the camper will resist the truck frame’s tendency to flex off-road. The Unimog boasts a torsional-free cab and bed mounting so that the cab and bed, or camper, allow the frame to flex without twisting your cab and home with it.
A Legend Doesn’t Come Cheap
If there’s any bad news I have to give you, it’s that Couch’s improved Unimogs don’t come cheap. Buying one would set you back about $385,000 for the truck alone. Just for context, one of the very old Unimogs that go about 45 mph could be had for under $50,000 while the super rare newer ones are closer to $100,000.
Granted, the base truck will be a capable machine and you can still build out a living space in the spacious rear. You can have the truck in two-door and four-door configurations, too. Couch quotes a payload of up to 12,000 pounds, which comes on top of the truck’s base weight of over 10,000 pounds.
If you aren’t interested in building out a camper, of course, you could take your Unimog to any one of the many expedition truck builders to have a camper mounted to the back. Couch estimates that a completed camper build could cost you around $600,000 or so total, depending on the camper box slapped onto the back. The end result should also get you a bit farther off of the beaten path than that $1m Ford F-550.
While the price may be out of reach for many, I’m happy the N.O.R.A.D. exists. For those Americans who can afford it, they can live out their dreams of traveling in one of Mercedes’ legendary trucks, but with power good for modern roads. If you want one, contact Couch Off-Road Engineering to get started.
(Photos: Author, unless otherwise noted.)
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