LEGO Technic has long been synonymous with intricate building experiences and authentic recreations of real-world machinery. The collaboration between LEGO and Mercedes-Benz has produced some truly iconic sets, and the LEGO Technic Mercedes-Benz Arocs 3245 (42043) stands as a testament to this successful partnership. For fans of Lego Technic Mercedes Benz models, and particularly those captivated by large-scale, functional builds, this set delivers an exceptional and immersive experience.
The LEGO Group’s foray into licensed Technic sets marked a significant shift, bringing the prestige and engineering excellence of renowned brands into the brick-built world. While LEGO Star Wars sets could be considered early licensed ventures in Technic, the 8110 Mercedes-Benz Unimog in 2011 truly kicked off the official collaboration with automotive giants. This set was groundbreaking not only for its Mercedes-Benz license but also for its impressive 2,048 pieces, making it the largest LEGO Technic set at the time. Following the Unimog’s success, sets like the 42030 Volvo L350F Wheel Loader continued to raise the bar, culminating in the release of the even more massive 42043 Mercedes-Benz Arocs 3245. Outdoing even the part count of the 42009 Mobile Crane MK II, the Arocs solidified its place as a flagship model in the Lego Technic Mercedes Benz lineup.
2015 was a banner year for LEGO Technic, and the 42043 Mercedes-Benz Arocs 3245 was a crown jewel of that year’s releases. This set not only surpassed previous size records but also deepened the collaboration with Mercedes-Benz. Even for those who aren’t experts in trucks or automobiles, the sheer presence and functionality of the Lego Technic Mercedes Benz Arocs 3245 are undeniable. It’s a model that immediately captures attention with its realistic aesthetics, minimal reliance on stickers, and comprehensive features including full suspension and innovative pneumatic components. The inclusion of new, longer pneumatic cylinders was a particularly exciting development for Technic enthusiasts. While minor imperfections might exist, they are easily overshadowed by the overall brilliance of the build and the finished truck. Considering its scale and licensed nature, the set was also offered at a reasonable price point (GBP 169.99, EUR 199.99, USD 229.99), making it an attractive proposition for Lego Technic Mercedes Benz collectors and builders alike. Let’s delve into the building process and explore the remarkable new elements that make this set so special.
Box and Packaging: A Premium Unboxing Experience
LEGO Technic flagship sets are known for their premium packaging, and the 42043 Mercedes-Benz Arocs 3245 is no exception. These sets often feature boxes with a large flap that opens to reveal the set’s key functions and components, enhancing the unboxing experience. The box for the Lego Technic Mercedes Benz Arocs 3245 is not only substantial in size, reflecting the set’s weight of over eight kilograms when packed, but it also introduced a welcome innovation: a flat-foldable design. This was a significant improvement for storage, as many LEGO enthusiasts accumulate boxes and appreciate space-saving features. The flat-foldable box was a first and a feature hoped to become standard for large LEGO sets.
Inside the box, you’ll find a meticulously packed collection of elements. A substantial instruction manual, exceeding 480 pages, guides you through the intricate build. A relatively small sticker sheet is also included, indicating the model’s aesthetic appeal largely relies on the brickwork itself. The parts are organized into numbered bags, divided into six build stages. This organizational approach, while potentially reducing the challenge for some seasoned builders, enhances the overall building experience by keeping parts organized and manageable, especially for such a large set. Inside, you’ll find five general bags of parts, two bags specifically containing Power Functions components (a battery box and an L-Motor), two bags holding a total of twelve tires, and a bag filled with pneumatic hoses, valves, cylinders, and a pump. This careful division into stages allows builders to focus on specific sections of the Lego Technic Mercedes Benz truck in a structured manner.
The Build: A Journey Through Engineering Excellence
Many LEGO Technic enthusiasts find the chassis construction phase to be the most rewarding part of building a large model. The initial stages, where the form and function are still emerging, offer a unique sense of discovery. The Arocs chassis is built in three primary sections: the front section using bags marked one, the central gearbox section from bags numbered two, and the rear section, including the rear axles and differentials, from bags numbered three. These sections are then connected using long liftarms and pins, creating a robust and satisfyingly large foundation for the Lego Technic Mercedes Benz truck.
The first stage, utilizing bags numbered one, focuses on the front of the chassis. Interestingly, these bags don’t introduce any new parts. Similar to the 42040 Fire Plane set, this stage includes the construction of a mock engine setup. While these inline engines are relatively common in Technic sets, the mechanism in the Arocs features a notable gear ratio increase to drive the six yellow pistons.
The most impressive aspect of the front chassis build is undoubtedly the construction of the two steering axles. This intricate mechanism uses a combination of pins and the Steering Arm 5 x 1 with Towball Socket (Design ID 15459), a part introduced the previous year. These front axles can pivot freely, their movement controlled by the Steering Arms and four sturdy yellow Shock Absorbers (Element ID 6027566). The steering is actuated through two links of different lengths: a Technic Link 1 x 9 (Design ID 32293) and a Technic Link 1 x 6 (Design ID 32005). This difference in link lengths, combined with varying steering rod lengths, ingeniously causes the two axles to steer at slightly different angles, enhancing the realism and maneuverability of the Lego Technic Mercedes Benz model. The steering mechanism is connected to a vertical axle that extends upwards through the chassis, ultimately linking to the emergency lights on the cabin roof via a gear system.
Although the construction of the two axles is very similar, the entire front assembly of the Lego Technic Mercedes Benz Arocs 3245 is a testament to clever engineering. It masterfully utilizes existing parts to create a complex system with multiple interacting and independent moving parts within a confined space. Building the front section is a truly captivating experience, showcasing the ingenuity of lead designer Markus Kossman and making it a highlight of the Lego Technic Mercedes Benz building journey.
Geared Up: Exploring the Gearbox and New Pneumatics
The second build stage focuses on the gearbox, positioned centrally within the truck. It bears some resemblance to the gearbox in the 8285 Crane Truck from 2009. This stage introduces the first new elements of the set. A new gear rack, 14 studs long and in Dark Stone Grey (Dark Bluish Grey), features both axle holes and round holes (Design ID 18942 | Element ID 6114979). This rack is designed to work with a new Bright Red (Red) bracket (Design ID 18940 | Element ID 6114965), 15 studs long and 3 studs high. These two parts, seemingly designed for each other, are somewhat specialized, potentially limiting their versatility in broader MOC (My Own Creation) building. However, when used together, they create a very sturdy and compact outrigger system.
The gearbox itself, while effective, is not as intricate as some found in other Technic sets, such as the 42042 Crawler Crane. The use of bright red 16-tooth gears is noticeable and might not appeal to all builders aesthetically; a less prominent color could have been preferred. The gears are primarily arranged on a single level, but the gearbox effectively serves its purpose.
This stage is also crucial for introducing the updated pneumatic parts. All pneumatic cylinders and valves in this set feature a new mold. The compressor pump, now in Bright Blue (Blue), is an updated version of the one seen in Medium Stone Grey (Light Bluish Gray) in sets like the 8110 Mercedes-Benz Unimog and 42008 Service Truck. The most significant change in the updated pump and other pneumatic elements (excluding the T-Piece and Pneumatic Hose Connector with Axle Connector) is the redesigned outlets, making it much easier to attach and remove the rubber pneumatic hoses. These updated parts have new Design IDs to differentiate them from their predecessors. The placement of the compressor pump, hidden deep within the model, is also noteworthy.
Back It Up: Rear Suspension and Differentials
The rear section of the Lego Technic Mercedes Benz Arocs 3245, built using bags labeled three, holds some interesting surprises, particularly in its suspension design. While no new parts are introduced in this section, the techniques employed are noteworthy. The suspension system is the highlight, and this section also incorporates the linear actuator for the tipping bed function, utilizing standard Technic techniques that are effective and reliable.
The two components housing the differentials are similar in construction and are connected by a small turntable, allowing the two axles to pivot independently. The inclusion of double differentials and double wheels on the rear axles demonstrates the designer’s commitment to detail and realism, catering to the desires of dedicated Lego Technic Mercedes Benz fans.
The axle components are attached to the rest of the rear section using two 6-stud long links. This arrangement, combined with shock absorbers (the softer spring version, Design ID 76138), prevents excessive side-to-side movement of the lower rear section. The entire rear assembly is then connected using Steering Arms with Ballsockets and Pins with Towballs, creating a multi-directional suspension system. This allows for independent axle movement and overall truck suspension, showcasing a significant difference in suspension design between the front and rear of the Lego Technic Mercedes Benz Arocs 3245.
Under Pressure: The Crane and Pneumatic System
The crane assembly is arguably the most complex and engaging section of the entire build. While it may appear straightforward initially, the extensive use of pneumatic hoses makes its construction a detailed process. Ensuring smooth functionality requires careful hose routing to avoid kinks or restrictions that could impede airflow. The sheer volume of hoses might lead to minor errors during assembly, emphasizing the importance of careful attention to the instructions. Due to the length of some hoses, extra space is utilized at the base of the crane arrangement, which also needs to be securely attached to the truck chassis. More explicit guidance on hose routing in the instructions would have been beneficial to ensure optimal performance of the Lego Technic Mercedes Benz crane functions.
The Lego Technic Mercedes Benz Arocs 3245 set includes a generous number of pneumatic components. Beyond pre-cut hoses and the updated compressor pump, the set features a total of four pneumatic cylinders. The set also includes familiar components like four valves and a small pneumatic cylinder, all with the updated mold and improved outlets. The image below illustrates the difference between the old and new versions of these pneumatic parts.
The set also introduces several brand-new parts. Firstly, a highly anticipated new turntable design. While appearing similar in size to the older turntable, the new version is slightly larger, lacks inner teeth, and features half-bevelled outer teeth (60 in total) for angled transmissions. The turntable comprises two inseparable parts (Design IDs 18938 and 18939 | Element IDs 6109283 and 6109285) that snap together securely, similar to the small turntable included in the set. The edge-based joining mechanism enhances sturdiness, and the new turntable offers smoother rotation. Given the extensive pneumatic hose system in the Lego Technic Mercedes Benz Arocs 3245, the older turntable design would have been insufficient due to space constraints.
Perhaps the most exciting new parts are the longer pneumatic cylinders, a feature long-requested by Technic builders since the introduction of the two-outlet pneumatic system in 1989. Despite the perceived decline of pneumatics with the advent of linear actuators, LEGO listened to fans and introduced both thick and thin longer cylinders. Both extend from 11 studs to 17 studs in length. The base of these new cylinders is a more convenient one stud wide, simplifying mounting compared to the previous two-stud width, although this adds one stud to the cylinder’s overall length. The thin cylinder, remarkably robust, also features a metal shaft.
The final new part is a new clamshell bucket (Design IDs 18942 and 18943 | Element ID 6109280), measuring 7 x 3 x 4 studs, consistent with other Technic buckets. These parts have both axle and round hole connections for versatile mounting. Once the crane assembly is complete, it attaches to the chassis using a ‘Dogbone Beam’ (Liftarm 3 x 5 Perpendicular H-Shape Thick, Design ID 14720) in the cabin and Pins with Bushes. Securing the crane section may require some force, and this is a good point to test all crane functions to ensure hoses are not obstructing movement. It’s also worth noting that the existing Axle and Pin Connector Perpendicular Double Split (Design ID 41678) in this set is made from a shinier plastic, with both old and new types potentially present in the same set, mirroring a similar change observed with the Axle and Pin Connector Perpendicular 3L with Center Pin Hole (Design ID 32184) previously. This might indicate a broader shift towards shinier ABS plastic for connectors, a change that might be aesthetically divisive among LEGO enthusiasts, particularly concerning iconic parts like the Axle and Pin Connector Perpendicular (Design ID 6536).
The Look Of It All: Cabin and Aesthetics
With the crane in place, the model begins to take shape, but the cabin construction truly brings the aesthetics of the Lego Technic Mercedes Benz Arocs 3245 to life. This enjoyable build phase, using bags numbered five, shifts focus from technical functions to the visual appeal of the cabin and tipping bed.
This stage introduces the final new element: a shield piece, previously seen in other sets and as a minifigure accessory, now printed with the Mercedes-Benz logo (Design ID 21100 | Element ID 6113039). The printed logo, rather than a sticker, is a welcome detail, necessitated by the shield’s curved surface. Another aesthetic enhancement is the introduction of the small Panel Fairing #22 Very Small Smooth, Side A (Design ID 11947) and Panel Fairing #21 Very Small Smooth, Side B (Design ID 11946) in White. These panels, introduced two years prior, now come in white, their sixth color variation. The cabin build prominently features the grille, a defining characteristic of the Arocs truck. The real-life Arocs grille has four rows, while the LEGO rendition features three. The bottom row is diagonally set but securely fixed at the back, utilizing a significant number of Pin 1/2 with 2L Bar Extension (Flick Missile – Design ID 61184). These are used in an impressive quantity of thirty, using the stud end to attach plates and the bar end to fit snugly into Technic Pins. The cabin construction is generally straightforward and attaches to the chassis with Technic liftarms, allowing it to tilt forward and reveal the inline engine.
Loaded: Completing the Tipping Bed
The final build phase focuses on the tipping bed, using bags numbered six. This section is acknowledged as the most repetitive part of the entire build. To mitigate monotony, some builders might choose to construct the tipping bed first, before tackling the more technically engaging sections from bags one to five.
The tipping bed construction mainly involves combining pins, beams, and panels to create a sturdy structure. A notable detail is the inclusion of a mechanism to open and lock the tailgate, further illustrating the designer’s attention to detail in this Lego Technic Mercedes Benz model.
Final Thoughts: An Astonishing Set Worth Owning
The LEGO Technic Mercedes-Benz Arocs 3245 is an exceptional set that leaves a lasting impression. The building experience is varied and engaging, particularly if the tipping bed is built first to break up the more technical sections. The engineering techniques employed are truly remarkable, resulting in a model that is both aesthetically pleasing and functionally rich.
This set is highly recommended for anyone who can afford it. It offers an amazing and rewarding build experience, packed with innovative techniques and new parts. The inclusion of full suspension and the new longer pneumatic cylinders in a Technic set of this size is truly impressive. While this review focused on the build process, techniques, and new parts, numerous online videos showcase the set’s various functions. One minor issue observed was a potential weakness in the crane lifting mechanism when fully extended, possibly due to a cylinder issue or the overall construction. However, this minor flaw is unlikely to detract significantly from the overall enjoyment of this astonishing set. The Lego Technic Mercedes Benz Arocs 3245 is a milestone in LEGO Technic design, raising anticipation for future licensed Mercedes-Benz trucks and other innovative creations from the LEGO Technic team.
Our thanks to LEGO Group’s CEE Team for providing this amazing set.
