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LEGO Technic Mercedes-Benz Arocs 3245 42043 Building Kit Review


The Lego 42043 set (the Mercedes-Benz Arocs) has many Technic fans going wild and it just so happens to be one of our favorite Lego cars to build. When we first came across this set, before our research, we thought it was just a MOC, but when we found out it was an official set, we were quite happy. The other big shocker to us was the price tag – that’s just something you have to take a look at for yourself to understand. After some research, this was definitely the set for us and we had to have it and here we are, writing a review for you so that you can determine if this is the set for you or not.

Here’s what really caught our eyes in the beginning:

The fact that this was designed by Markus Kossmann should be more than enough. This is a designer of various LEGO Technic’s Flashship models.

The amount of pieces it has was astonishing. It has a total of 2793 pieces and if we’re correct, this is one of the largest Technic sets to date.

The Box



With large Technic sets like this, you can automatically assume it’s going to come wrapped up in a big box. As we stated in the beginning, this set contains 2793 parts, so the box needs to be pretty big. It’s just as big as the 2014 flagship technic Lego 4230 set.

On the box, you’ll find a couple of images of the Mercedes-Benz Arocs and on the sides of the box, it describes the Pneumatic System. On all of the sides, there’s the new Pneumatic System V2 logo. You’ll also find this logo inside the flap.

When you flip the box over and look at the back, you’ll find images of the B-model construction truck.

The box is, as expected, large and heavy, which in our opinion, is a pretty good sign. Inside of it, you have lots of bags, each one is numbers one through six, except for the one that contains the pneumatic parts. Also, the battery box isn’t in a bag, it is just sliding around in the box, protected by the plastic bags. The instruction book has also been packaged in plastic, so you don’t have to worry about any folded pages.




Instruction Book


Above is a picture of the nice looking instruction book. This contains 471 pages of well-written instructions that are easy to understand. With the other Lego sets that we put together in the past, the instructions came in a couple of booklets, which was okay with us, but I personally like simply flipping through the pages of one book.

With using one book, when we are ready to take a break (we take numerous breaks throughout the building process), we can simply place a bookmark in the book so that we don’t lose our place when we get back.

In the same plastic bag as the book, there’s a sticker sheet. We usually aren’t too big on stickers, but this sticker sheet was pretty cool and had that nice high quality feel to it.

Amongst the parts, you’ll find a pretty cool customized number plate – this license plate shows us that Markus Kossman is the designer.

Now, back to the stickers – they are numbered 25 and are for the B model – Mercedes Benz Arcos 1845.


The Parts

The parts come in a total of six numbered bags. As with most of the Lego sets we put together, we’re happy to know that they care to organize all of the Legos. Without this type of organization going on, putting the build together would be hard. When you’re building anything, organization is the key and this is obviously something that Lego recognizes.


Here’s a look at the parts:




Build One

The front chassis is a pretty interesting build. This build consists of two independent front axis, each having their own suspension. The steering is controlled by a hand of god mechanism. This mechanism is camouflaged as the orange hazard lights. To steer the vehicle, you can twist either one of the lights.

The way the axles turn were really interesting. There’s some pretty clever linkages going on here. Through these linkages, the front axle is able to turn 28 degrees, while the second axle is capable of turning 19 degrees.

In the front chassis, you will be placing the L motor and eventually, later on in the steps, it will also be housing the battery box. The battery box will gently slide down between the hazard lights.


Responsible for suspending the axles, you have the three Beam 4M Cups.

In this set, you have the new Cross Axle 2M W Friction Pin.

In bag number four, you’re going to find the new shovels, which are really neat.


Build Two

In the second build, you’re going to be focusing on the rear chassis. Like the first build, this is also fun to put together. The rear chassis has independent suspension and dual differentials.

Holding the duel axle differential assembly, you have the four Beam 4M Ball Cups.

There’s a total of two 6M Track Rods that will be used as Panhard Rods.

For the first time since the 8285 Lego truck, which was released back in 2006, this build has rear axles with twin tires.




Build Three

During build number three, you’re going to be focusing on both the outriggers and the gearbox. During this time, you’ll also be embedding the blue Pneumatic Pump within the gearing. This is a fun process as well.


On the left, you have the old Gear Wheel, the 2M Gear Shifter Connector and the 2M Gear Shifter Ring. On the right, you have the Gear Wheel, 3M Gear Shifter Connector and the new 3M Gear Shifter Ring.

The outriggers consist of new parts like the 14M Gear Rack and the 15M Gear Rack Housing. You can activate the outrigger jacks manually, which if you are familiar with some of the later sets, is an improvement on the power driven jacks. Believe it or not, these are actually strong enough – so strong that they can lift the truck.


Build Four


In build four, we will be focusing on the pneumatic arm and trust us, you’re going to have a lot of fun with this one. The pneumatic arm is the more complicated build of this set. So, before you move to build four, you may want to go for a break, because it is going to take a tad bit longer than the other builds in this set. When you approach this build, you will need to clear your desk and get ready.

This is a new Pneumatic System that consists of one air pump and three pneumatic rams. The small ram is only 5M long, but it is capable of extending out to 7M. The medium and large rams are 11M long and are capable of extending out to 17M.

What’s really neat about this build is the fact that the air hoses are color coded. The color grey extends to the rams, while the blue color is the air supply and black retracts the rams.

There’s eight pneumatic tubes that pass through the turntable – a new big turntable that doesn’t have any teeth is used on the inner ring. There’s four pairs of hoses – all of those are threaded into four separate colored beams (blue, grey, yellow and black).

When it came to completing the step with the eight hoses, it took two different attempts, but we eventually got it right. When we threaded the hoses, following the order of the instructions, the hoses ended up getting twisted up in the turntable, which was a bit annoying because it wouldn’t let the arm rotate. So, here’s a little tip for you – Wait until you have threaded all eight of the hoses through the turntable before you start to thread the hoses into their colored beams – this will save you from a headache of having to deal with tangled hoses.

On each side of the arm, you’re going to see a total of two pneumatic two-way valves.



Build 5

In module five, you’re going to be focusing on the cab, which is a whole lot easier than build number 4. When you finally reach it to build number 5, give yourself a pat on the back, because this means you have made it past the hardest build (number four) in this set. Now, number five will have you making the cab and the front bumper as two separate components.

On the shield, the Mercedes Benz logo is printed, which we believe was a nice little touch.

In the cab, you have two blue seats, a printed dashboard, a steering when and some wing mirrors that are responsible for guiding the driver.




Build Six

Congratulations, you’re almost there! This right here is the last build and you will be focusing on the tipper cargo tray, which isn’t hard at all. By now, you’re probably pretty excited to get this bad boy on display.


Additional Information

What’s really cool about this model is that you can put together all six modules independently. If you’re familiar with Legos and have worked with other Lego sets before, then you’re probably aware that most of them involves building onto a foundation. This one, however, is different. You can build all six parts independently, then put the full set together in the end. It’s really fun watching all of it come together perfectly in the end.

The arm is not going to sling forward as it has been constrained to an arm of 180 degrees. The left gear lever is responsible for controlling the outrigger arms as well as slewing the nice pneumatic arm.

As for the right gear lever, it is responsible for controlling the tipper tray as well as the air pump.

On the tipper tray gate, there’s no lock.

The right pneumatic controls are responsible for operating the third and lower rams.

The left pneumatic controls are responsible for operating the grab bucket as well as the middle ram.

As for the cab doors, those are pretty cool, because you can open those up. When you open up the cab doors, the entire cab will tip forward and you will see the 6 cylinder engine. The white color of the cab looks clean and is a very basic interior.


The Cabin

Looking at the trucks cabin, you’ll discover how neat it looks. It looks so much like the real deal. The overall shape of the cabin is surprisingly smooth. Looking at the cab, unlike with some of the other models, this one doesn’t lack any detail. It has all of the lights, mirrors, and horns present. Seeing all of these features makes it obvious that Lego did their research and put attention into making sure they got the cabin right and that makes us proud.

We absolutely love how they did the front grill. However, on the same note, we feel that it would have looked a little better if they made it so that the middle part of the grill was angled as well, but that’s not that big of a deal. It just seems a bit on the odd side to only have the angles at the lowest part.

The Building Process

Personally, we feel that the building process was a whole lot of fun, except for the fourth build – we would personally hate to have to redo that build, but since we know what to do, it’d probably be easier. When it comes to building, the process is very straight-forward and the steps are easy to follow. First, you start off with working on the chassis, then you work from the front to the rear. Afterwards, you’ll be putting the cabin together, then the crane and you’ll be finishing it off with the bed.

As we said, when you get to the crane, it will require some studying of the instructions in order to get that tubing through the turntable without getting it all jumbled up. The instructions do give you clues on how to do it, but this is something you really need to read and put extra attention towards or you’ll end up like us – in one big tangled headache.

When you finish building the truck, you’ll see that it’s not really all that big. It’s fairly small, but at the same time, it’s pretty heavy.

All around, there’s a live-axle suspension system. Apart from the suspension system being a tad bit on the hard side, it works pretty good. The one big downside we can find in regards to the suspension system would be the fact that the truck is sitting high on the wheels. If the suspension travel was as big as the gap between the fenders and the wheels, this wouldn’t have been a problem. Even when you have it fully compressed, you still have two studs room right above the wheels.

When it comes to the drivetrain, there’s no complains – that was simple and smooth. Responsible for driving the engine, you have the two rear axles that are properly hidden under the cabin. The inline six turns at a nice speed and when it’s turning at higher speeds, it makes a pretty cool rattling sound. Unfortunately, you cannot see this from outside when you’re driving it around because it is hidden out of sight by the cabin, but that is expected. Speaking in the cabin, it folds up neatly, and even then, you will be able to see the four cylinders. With some effort, you will be able to see the fifth cylinder, which is hidden under the battery box. The sixth cylinder, however is invisible and hidden underneath the crane.


Battery Box

We feel that the battery box in this set is worth mentioning. It’s not really visible at all – it has been hidden in the back of the cabin – you can easily replace it.

Crane Rotation

Once you have the build put together, you can rotate the crane, which is really neat. The crane uses just the right speed to rotate it – you know, the speed that doesn’t spend so slow that it becomes boring, but at the same time, you can position it precisely. The downfall to the crane rotation feature would be the fact that it is limited to that 180 degree rotation. The pneumatic tubing that runs through the turntable limits it to only turning in half a circle. Mind you, we’re not saying it should do a 360 degree turn, but being able to turn it just a little bit more would have been nice.

All of the cranes functions, except for the rotating utilizes the pneumatic pump. The lowering, raising, and extending of the crane are all impressive. Overall, we believe this crane is really good. The only downside in this function would be the bucket. For some reason, we had some trouble opening it up and yes, it can swing in all directions, but it doesn’t do so due to the stiffness of those pneumatic tubes. Personally, we would have also liked if it were able to turn, but we understand how the pneumatics prevented this from happening and we’re perfectly fine with this.

This bad boy has been well engineers and overall, it is one of the most memorable Lego sets we have ever put together. Apart from that bucket, in terms of performance, we don’t have any complaints. When it comes to the pump, it doesn’t have any trouble moving the crane around and the tubing that runs along the crane helps give the build a more realistic feeling. Of course, the tubing on the crane does make it look bigger. Looking at it from ground level, you can kind of tell that the crane is 10 studs higher than the cab roof, but when you look at the build from a bird’s eye view, you cannot tell.

Tipping of the Bed

The last power function we’re going to talk about is the tipping of the bed. This is done bia a large linear actuator. You can lock the rear hatch using a handle that is located on the side of the bed. You can pack the cargo bay with bricks, without losing any of them during transport because there are practically no holes in the cargo-bay. Unloading that heavy load of br5icks isn’t going to be a problem either.



Overall, Lego 42043 was a lot of fun. All of the functions are amazing and are easy to control, making this a playable set. The cabin is convincing and done correctly and the crane works smoothly. This set is a bit on the pricey side, but once you put it together, you’ll see just how worth it, it was because of how much fun it is. After you put this together, we recommend Lego 42039 set, the lego 76023 or the Lego 42056. However, if you’re not interested in Lego cars after this, you may like the Lego Hulk.

Now, we’re going to leave you with the following pictures:










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