30 December 2023

LEGO® Technic™ set reviews: 42163 Heavy-Duty Bulldozer and 42167 Mack LR Electric Garbage Truck

Posted by Alex Campos

Here at New Elementary we’re looking ahead to what the New Year will bring to the LEGO® Technic™ theme with two January 2024 sets: 42163 Heavy-Duty Bulldozer and 42167 Mack LR Electric Garbage Truck. Since neither set is very large, we’ll take a look at their elements and their builds together.

Products in this article were gifted by The LEGO Group; the author's opinions are their own.
This article contains affiliate links to LEGO.com; we may get a small commission if you purchase.  

42163 Heavy-Duty Bulldozer
US$12.99/ £8.99/ 9.99€/ AU$14.99
195 parts
1 January 2024
Set 42163 on LEGO.com

42167 Mack LR Electric Garbage Truck
US$32.99/ £29.99/ 34.99€/ AU$59.99
503 parts
1 January 2024
Set 42167 on LEGO.com

New moulds

There’s a single new mould, found only in the Mack truck. The LEGO Technic presentation at Recognised LEGO Fan Media Days in September mentioned a new type of knob gear, and here it is.

  • 1x Technic Knob Wheel with Axle Hole 45 Degree (6469530 | 5405)

At first glance this looks far from new; the Knob Wheel (32072) has been with us since 1998. But a closer inspection reveals a significant difference: the axle hole in the centre is rotated 45º relative to what we’re used to.

The image above shows the sole knob wheel that comes with 42167 with the original version on the left and the new “phase-shifted” version on the right. There are some other differences, such as axle hole design and arm reinforcements, but these are minor compared to the 45º rotation.

“The axle hole is rotated... so what?” Well it’s important when pairs of knob wheels are meshed together.

To be able to mesh, one knob wheel has to be rotated 45º relative to the other. If both knob wheels are of the same type, as above, one of their axles will also be rotated. If the axles need to be aligned, like on a claw, this presents a problem.

If we replace one of the knob wheels (in this case, the one on the right) with the new version, the 45º rotations of the wheel and its axle hole cancel each other, allowing for perfect alignment.

This feature also applies if the knob wheels are meshed in their other popular configuration: 90º to each other. In this example, the new version allows both the steering yoke and the hand-of-god control to be properly aligned.

It’s important to not mix up the two knob wheel versions or, depending on the mechanism you’re building, things may not work. This is why, at least for now, the new version only comes in Light Bluish Gray to distinguish it from the Yellow or Black we normally see in the older variant nowadays. 

But beware... there is a single set from 2005 that features the old version in Light Bluish Gray, seen above on the left from 8415 Dump Truck. If you’re looking for a knob wheel in your parts drawer or searching a seller’s inventory, make sure you’re getting the type you need.


Once again, it’s the Mack truck that provides the single recolour.

  • 3x Technic Beam 1 x 7 Thick with Alternating Holes in White (6471586 | 2391)

Elements with pin holes in several orientations, such as flip-flop beams, are extremely useful to build strong and versatile structures. This particular length, introduced in 2023, was previously available in Green, Red, Dark Bluish Grey and Black. A new colour, especially a “regular” one like White, is always welcome.

Speaking of the colour white, while building I noticed that the white Technic Pin Connector Hubs with 1 Pin with Friction Ridges Lengthwise (6282148 | 65487) were of a slightly different shade than the other white elements. This mould is infamous for colour inconsistencies in 42115 Lamborghini Sián FKP 37; that time in Lime instead of White.

This consistent colour inconsistency, as well as the difficulty in inserting it in other elements’ pin holes, makes me suspect that for some reason this part is made of a different material than most other Technic elements. This suspicion is further compounded when illuminating the back of 42121 Heavy-Duty Excavator, which contains this mould in yellow, with the M:Tron fan’s essential tool: a UV torch. Amidst the abundance of yellow, this is the only element that fluoresces. I’m not sure why the need for a different material: perhaps it needs a bit more flexibility to avoid cracking due to repeated insertions and removals? Still, these inconsistencies are ugly and definitely shouldn’t happen in such expensive products.

Rare elements

The following elements appeared previously in one other set.

Regarding the Cube, it’s uncommon to appear unprinted, and as such it could be useful for MOCs. Therefore I thought it warranted a quick analysis.

Although it has a 2x2 arrangement of studs at the top, it actually occupies a 3x3 area. Its height is exactly 2 bricks. This makes its dimensions 24x24x19.2 mm (studs excluded), so, despite the name, this isn’t a perfect cube.

The inside matches the outside, with a 2x2 arrangement of antistuds. Its top wall (ceiling?) has a thickness of 1 plate, so you can fill the inside with one 2x2 brick and two plates.

There’s a gap between the 2x2 pieces inside and the walls of the Cube. That gap is too narrow to fit a tile, but slimmer parts, such as the neck bracket (28974), might work. Unfortunately, I don’t have any to test this.

Next, I wanted to see what could be done with the exterior. I wasn’t able to achieve any useful results with the first two brackets I could think of. As this is, in practice, just a 3x3 square with 2x2 studs in the middle, it shouldn’t be hard for more talented SNOTters than I to figuratively bend this element to their will.

The following elements appeared previously in three other sets.

  • 3x Technic Beam 2 x 3 L-Shape with Quarter Ellipse Thick in Dark Stone/ Dark Bluish Grey (6353303 | 71709)
  • 1x Technic Beam 3 x 5 L-Shape with Alternating Holes in Black (6408182 | 2477)

Other elements of interest

42163 Heavy-Duty Bulldozer doesn’t contain any unique, or even rare, elements. However, due to its low price, it can be a cheap, useful source of some parts.

  • 48x (plus 2 spares) Technic Link Tread with Beveled Edge in Black (6047885 | 15379)
  • 2x Technic Beam 2 x 3 L-Shape with Quarter Ellipse Thick in Bright Yellow/Yellow (6332412 | 71708)
  • 4x Technic Gear 16 Tooth with Clutch on Both Sides in Red (6100930 | 18946)

Interestingly, this set contains 4L axles in both black and red. While I understand and appreciate the presence of black to avoid colour clash in this small set, I don’t see a need here for red. Maybe there was a surplus of red axles in the warehouse, so they were used here in places where the colour wouldn’t clash?

42167 Mack LR Electric Garbage Truck includes a few more elements of interest.

  • 3x Technic Panel 3 x 7 x 1 in White (6345328 | 71709)
  • 1x Technic Beam 2 x 3 L-Shape with Quarter Ellipse Thick in White (6345327 | 71708)
  • 1x Technic Panel Fairing #7 3L Very Small Smooth, Side A in Black (6426589 | 2387)
  • 1x Technic Panel Fairing #8 3L Very Small Smooth, Side B in Black (6426590 | 2389)
  • 5x Technic Axle Connector Smooth [with x Hole + Orientation] in Brick Yellow/Tan (6262188 | 59443), in this colour for the first time in Technic
  • 2x Technic Pin Connector Hub Perpendicular 3L with 2 Pins in Medium Stone/Light Bluish Grey (6408168 | 2393)
  • 4x Technic Beam 1 x 11 Thick with Alternating Holes in Medium Stone/Light Bluish Grey (6408168 | 73507)

Sticker sheet

Only the Mack truck has one.

The colours in the stickers aren’t very varied, but go well with the theme of the vehicle. Its appearance doesn’t lose much if you don’t apply the stickers. The exception is the front, because stickers are what provide the truck’s headlights.


The number of LEGO Technic sets with B-models has been steadily declining for the last few years. Lately, the smallest sets were the last bastion of this tradition that began right at the beginning in 1977.

Well, 2024 could be the year the B-model finally goes extinct. Not even 42163, the smallest set in the wave, features an official B-model. It all now rests on the shoulders of fans, congregating at sites like Rebrickable, to provide alternate models for sets.

The builds

Neither set was particularly challenging to build, fitting with the recommended minimum ages of 7+ for 42163 and 8+ for 42167.

Taking a look at the Bulldozer first...

This is a tiny, cute and, dare I say, almost chibified machine. It takes some design cues from 42131 Cat D11 Bulldozer, but with black regular treads instead of yellow triangular ones. That, and the absence of Cat licensing.

The back is bare, almost begging for a ripper, even if manually operated.

As soon as I saw this set, it reminded me of the previous “cute little bulldozer”, 8259 Mini Bulldozer from 2009 (on the left in these images). They could almost be long-lost brothers, with practically the same size and the same functionality: worm-driven blade raising.

One major difference, apart from the absence of B-model, is the colour and type of track sprockets: regular grey 16T gears for 8259 and clutch red 16T gears for 42163. At first, I thought the usage of the clutch gears instead of regular ones was a disadvantage because it breaks the colour scheme and is less versatile for alternate builds. But then, after building both models, I noticed that 42163 rolls more freely on smooth surfaces without sliding like 8259. This is most likely due to the clutch gears being attached to the body via regular pins, which can freely spin on both ends, while the regular gears are attached via axle pins and spin on only one end.

Here you can see the range of motion for both machines’ blades. The results are similar, even though the mechanisms for raising the blades are quite different between them.

Let’s now look at the Mack truck.

This is a very well-proportioned truck, with a drab yet realistic colour scheme. Its width of 9 modules (plus rearview mirrors, claw and hand-of-god controls) almost make it LEGO City-scale, although any minifigure trying to squeeze into the driver’s seat will have a really bad day.

This is the floor of the chute section, built from a lot of plates, tiles and slopes. I don’t remember seeing such a dense LEGO System build in a LEGO Technic set in a very long time. It is used to redirect the garbage that comes from the grabbed bin into the truck’s container, and I bet the designers went through a lot of iterations to make something that’s compact and works well enough.

This panel almost boasts the complete collection of pin colours!

The truck features hand-of-god steering and I discovered the left wheel rubs against the wheel arch when fully turned left. Sadly I don’t see an easy fix for this that doesn’t compromise the turning radius which isn’t that generous to begin with.

The truck’s main function is the grabbing and lifting mechanism. With a single turn of a knob on the left side of the vehicle, the claw grabs the bin, and then lifts it to dump its contents inside the container. This kind of grab-then-lift functionality was previously present on sets such as 8094 Control Centre (the robot arm model), 8479 Barcode Multi-Set (the garbage truck model) and 9736 Exploration Mars, but the utilisation is most similar to the Automated Garbage Truck LEGO Ideas project that wasn’t approved for production.

I replaced the new knob wheel with a second copy of the old version, just to see how the model would look and, as expected, the claw looks awful and works poorly. This is a great example of how useful the new version is.

The set comes with a garbage bin to picked up and dumped. There’s also red and blue 1x1 round tiles, 3 of each. Due to the elements that comprise the bin, only its upper half is usable to store garbage.

The third function is tilting the container to dump the garbage, hopefully at a recycling centre. A simple linkage accomplishes this and the rear hatch is opened automatically by gravity.

Finally, the driver and passenger doors can open. There’s a gaping hole when you open each door, but I prefer it over not having functional doors at all.

I noticed the usage of White Technic Beams 1 x 2 Thick with Pin Hole and Axle Hole (6265135 | 60483) on the rear corners of the truck. I think “toilet paper panels" (89679) would work a lot better here and they became available in White in 2023.

Since I don’t have any of these panels in White, I used one in Vibrant Yellow to imagine what it’d look like, and indeed it looks much better. Perhaps the designer wanted to use such a panel here, but budget concerns forced some cut corners (or in this case, expanded corners), resulting in the usage of another element already present elsewhere in the set.

The truck has great proportions and wouldn’t look much out of place in a LEGO City layout, but those A-pillars are kinda chubby. I tried replacing the 5L beams with their thin variants (here in grey because that’s what I had on hand), and the look is significantly improved, with the bonus of allowing the rear view mirrors to be more separated from the rest of the vehicle.

It does leave many pins partially exposed, however. To solve that, a new mould would be quite useful. Just like there’s a half-width version (32123b) of the Technic bush (3713), there could be a half-width version of the 1L beam (18654). Then again, I’m not sure if TLG would want to introduce such a part, as it would incentivise the insertion of pins half-way into holes, which damages the pins in the long term.


42163 Heavy-Duty Bulldozer is very fun to drive around, push LEGO bricks and annoy pets. Its price of £8.99 / $12.99 / €9.99 won’t break the bank, either. But it doesn’t offer anything new for diehard LEGO enthusiasts looking for new moulds or colours, and 42148 Snow Groomer offers a lot more functionality in the same price bracket (plus it has the added value of an official B-model) and provides a more interesting parts inventory. So, unless you’re specifically a big fan of bulldozers and/or construction machines, you’ll be better served with the groomer.

42167 Mack truck is weirdly priced; considerably cheaper in the US than in Europe (£29.99 / $32.99 / €34.99). Could this be due to Mack being an American brand? Regardless, this is a compact model filled with dense functions, and a good alternative to the B-model of 42078 Mack Anthem if you can’t find or afford it. The new knob wheel shows its usefulness well here, and the abundance of white and green elements is welcome.

How the heck am I supposed to push this thing into the garbage bin? And how will it fit anyway? I know the mantra “If it fits, I sits”, but this is ridiculous.

READ MORE: LEGO® Star Wars™ set review: 75371 Chewbacca

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  1. Nice review. Thank you especially for pointing out other prior instances of the dump truck's grabber arm mechanism. I'm not usually one to accuse Lego of appropriating designs, but taken alone it was suspiciously similar to the Ideas submission.

  2. Very nice and thorough review! I had the chance to review both sets too, and I agree with you on everything you pointed out. I also found disconcerting the axle that hinges the back door: it was left incomplete and asimmetrical! If you just add a spacer and a bush, you get a better look and the door still works perfectly.

  3. I feel like the dozer is meant to evoke the triangular tracked look, but at such a small scale it'd be hard to fully commit to adding a third gear, so they just let it drape over the connector to imitate the shape.