For many, the 435 (sales designation U1300/U1700) is the ultimate
Unimog. It has phenomenal off-road abilities and is one of the most
capable and comfortable Unimog models available. Its tremendous
ground clearance, extremely flexible suspension, and superior drivetrain
allow the 435 to easily transverse terrain that other vehicles would
not even be able to approach. The 435 is a vehicle that can be used
in the most demanding circumstances, from harsh frozen terrain in
the arctic to the scorching hot sands of the Sahara. The 435 also
has the ability to carry heavy equipment, supplies or implements
without sacrificing its’ off-road ability. Whereas previous
Unimog models were relatively slow and basic, the 435 has a comfortable,
ergonomic, and functional cab and is equally as capable on-road
The 435 Unimogs are part of the SBU range. Like other Unimog ranges,
there are many variations within the SBU range such as the 424,
425, 427, 436, 437. All of these vehicles are very similar and differ
primarily on engine specifications and wheelbase. Like other SBU
Unimogs, the U1300 and U1700 are characterized by their boxy cabs
that are larger and much more modern then previous types of Unimogs.
The 435 models were introduced in 1976 and built until 1988 when
they were replaced by the very similar 437 which are still being
produced. The 435 represented a dramatic change for Unimog in terms
of comfort and capability. The 435 has a comfortable, if somewhat
basic, cab that provides excellent ergonomics, heating and ventilation,
and insulation from sound and the elements. For the first time,
the Unimog had a level of comfort and ergonomics comparable to other
commercial on-road vehicles of its day. As a matter of fact, the
435 cab is similar to that of the 1980’s VW Vanagon in that
they both use similar interior materials and layout, and have a
comparable level of creature comforts and noise levels. By modern
standards, this may be a bit basic but it is very functional. The
standard cab is an enclosed two door although four door DoKas were
also produced in small numbers. A soft top was not offered except
for in a few special military applications. Options such as air
conditioning, air suspended seats, additional soundproofing and
auxiliary heat were also available. While making major improvements
in comfort and on-road capability, the 435 did not sacrifice off-road
capability. It maintained the Unimog off-road design principles
and took them to an even higher standard.
The major difference
between the U1300L and the U1700L is that the U1700L has the turbocharged
170 hp engine and has heavier duty axles. Otherwise these vehicles
are essentially the same. The 435 uses the same 352 engine as the
406/416 but in a higher state of tune. The U1300L has a normally
aspirated 130hp OM352 while the U1700L has a 170hp turbo charged
The U1300L and U1700L have 128-inch wheelbase. The U1300L also came
in a long wheelbase version called the U1300L/37 and this had a
3700 mm wheelbase. The U1700L also came in a long wheelbase version,
the U1700L/38 with a 3850 mm wheelbase.
435s have an eight-speed forward and eight speed reverse gearbox.
This is not a 2 x 4 shift setup as with the 406/416, but a straight
8-speed gearbox. There are two auxiliary gearboxes available, which
allow for high, low and super low. High is 1:1, low is 5.76:1 and
super low is 55.87:1 giving crawl ratios lower than 4500:1! As with
the 406/416, torque converters and double clutch PTOs are available.
In addition, the gearbox can be mated to a hydraulic motor for hydrostatic
drive that provides for extreme control. Finally, there is an overdrive
available for the 435 that makes it a much more relaxed than previous
Unimogs when cruising at or above 50+mph.
The 435 have power steering and air assisted power brakes with disks
on all four wheels. In addition the rear brakes are proportioned
to load. The standard final drive ratio is 6.5:1. High-speed axles
provide a 5.3:1 ratio. With the standard tires and axles ratios,
the top speed of a 435 is aprrox. 52 mph. With the high-speed axle
ratio and 14.5R20 tires the top speed is approx. 65+ mph. The overdrive
allows for a top speed of 70+mph but is really best suited to lower
the RPMs while cruising at 60+/- mph.
Unimog 435 is an impressive vehicle and larger than previous Unimogs.
At first it can be quite intimidating because of its large proportions.
It’s size is deceiving and it is much more nimble than it
appears. It has an extremely tight turning radius, and with the
power steering and slow crawling capabilities, it can maneuver in
very confined places. A U1300 even fits in most urban parking spaces!
However, the 435 is often a bit too big for most recreational off-roading
although other than it’s height, it is much more nimble than
a Hummer H1. It’s size and capabilities make the 435 ideal
for emergency work, backcountry industries and for major expeditions
to remote areas. In these roles, the 435 is truly in a league of
its own. With a four ton payload rating and its off-road capability,
the Unimog can get supplies, equipment or water to remote emergency
locations more quickly, economically and safely than by virtually
any other means. That is one reason why so many emergency crews
throughout the world, from Germany to the USA, and from China to
South Africa, use the 435. Virtually every government in the world
uses Unimogs either through their armed services, municipalities
or emergency crews. For example, in the United States, Unimogs are
used in the Armed Forces, by federal agencies, state agencies and
Like other Unimogs, the 435 is designed primarily as a tractor and
implement carrier. As a result, the 435 takes a number of front
and rear PTO options including 540-rpm double clutch units. In many
applications PTO horsepower is limited only by engine output, which
means the 435 can have up to 170HP at the shaft which puts it in
the league of dedicated heavy-duty machinery and allows for serious
implements such as large snow blowers. In addition, many 435 Unimogs
take standard 3 pt hitch front and/or rear with a PTO driven shaft.
In addition, the 435 can be fitted with single or dual circuit,
multi-cell, hydraulic systems with 25+ gpm pumps. As a result, the
435 can accept an extremely wide range of implements, from backhoes,
front loaders and cranes; to snow blowers, tillers, and brush cutters.
course, the 435 also makes an incredible expedition vehicle. It
is considered one of the best platforms from which to build a high-mobility,
long-range and self-contained expedition vehicle. The unique chassis
and rear platform design mean that the bed and rear load space are
free of any twisting or torsional stress which keeps a rear body
from being torn apart in extreme conditions. An incredible amount
of space is available for rear bodies or custom modifications due
to the 435’s efficient cab forward design. The high payload
capacity means a lot of water, fuel and supplies can be brought
along without stressing the vehicle or reducing its capabilities.
For example, a Land Rover 130 and a standard 435 have the same wheelbase,
yet the 435 has more than twice the payload capacity and twice the
space of a 130. Furthermore, the 435 has a much tighter turning
radius, much better approach and departure angles and almost twice
the ground clearance. The Unimog is also much stronger than the
130 in virtually every respect. It’s no wonder that most of
the world’s most capable expedition vehicles are based on
the Unimog 435.
The SBU Unimog is a great vehicle and in many ways represents the
ultimate Unimog. They are comfortable, capable and very versatile.
Most owners have found that there is no need to make any serious
modifications. However for specialized applications there are a
number of improvements and upgrades that can easily be applied.
Unimog 435 Options
Most U1300 and U1700
Unimogs come with the Mercedes OM352 engine. This is an excellent
and extremely reliable engine that is used in Mercedes trucks and
in marine and industrial applications. U1300 Unimogs normally come
with the naturally aspirated130hp engine. Although 130hp doesn’t
sound like much, these engines have a tremendous amount of low-end
torque and move a U1300 along quite well. However, a 170hp turbocharged
OM352A is a direct replacement and bolts right in. The original
engine can be turbocharged, however there were modifications made
to the turbo version engine, such as extra oil passages and extra
cooling, to allow it to handle the extra heat and stress caused
by the turbo. While many have successfully installed a turbo on
the original engine, the best method is to use an OM352A engine
that was originally intended for a turbo.
In addition to the OM352 and OM352A, the OM 366 and OM366A are also
used in SBU Unimogs and can easily be installed in a U1300 or U1700.
These are direct replacement engines and can be installed using
genuine Mercedes parts. The OM366 engine has between 130 and 214
horsepower, depending how it is configured. In addition to more
power, it is a more modern, cleaner burning engine that is also
somewhat more fuel-efficient. Like the OM352, the OM366 is an extremely
durable and reliable engine.
Of course either the OM352 or the OM366 can be custom tuned to bring
out more than stock horsepower. The OM352A can be tuned to between
200-225 HP whereas the OM366A can be tuned up to about 250-275 HP.
However these are not Mercedes approved modifications and may affect
the longevity of the engine.
Special Drive Train
540 rpm front pto
H igh Speed Variable rpm front PTO
540 front rear PTO
540 front rear PTO double clutch driven
540/1000 RPM shiftable PTO double clutch driven
that works in all gears forward and reverse. The gear-splitter
increases any gearbox ratio by 22% when engaged.
There are several auxiliary
under drive gearboxes available. These gearboxes are installed
as auxiliary gearboxes to the stock gearbox and can be engaged
in all gears forward and reverse.
-3.19:1 for a crawl
ratio of approx. 271:1
-5.76:1 for a crawl ratio of approx 490:1
-55.87:1 for a crawl ratio of approx. 4750:1!
*The 55.87 gearboxes must be added onto the 3.19 or 5.76 gearbox.
High Speed Axles:
The standard axle ratio for the U1300 is 6.5:1 and for the U1700
it is 6.4:1. With the optional high speed ring and pinion the
ratio for the U1300 is 5.3:1 and 5.4:1 for the U1700. This translates
to approximately a 19% increase in the overall ratio.
The stock tire size
is 12.50x20. However 14.50x20 fit without modification. Other
sizes such as 11.00x20, 12.00x20, 13.00R20, 12.00R22.5, 14.5R24
are options and even extreme high flotation tires such as 22-20
tires are possible.
The stock cab, even
with the standard army seats, is quite comfortable and the ergonomics
are excellent. The power steering, power brakes and soft coil
suspension means the 435 is comfortable and easy to drive. However,
by modern standards, the cab is a bit basic and somewhat noisy.
There is no need to shout or speak particularly loud but extra
sound insulation can bring the noise levels down to a point that
the cab is actually quiet. Orthopedic air seats, radios, heated
windshield, extra heaters, carpeting, etc can all be added to
make the cab even more comfortable.
Here for a detailed list of 435 specifications and weights