LEGO Technic 42131 Cat D11 Bulldozer

LEGO Technic set 42131, “Cat D11 Bulldozer”, depicts a tracked construction bulldozer inspired by a Caterpillar machine.

This model belongs to the Technic tradition of functional construction machinery. Its tracked base, front blade and rear ripper identify it as a Cat D11 Bulldozer, with the focus placed on the vehicle’s engineering and working features rather than on a character-based scene.

The build uses 3854 pieces and creates a dense Technic structure designed around movement and mechanical detail. Notable known features include the tracks, movable work equipment and app-controlled motorisation, all tied to the model’s construction-vehicle subject.

The set is aimed at Technic builders who are interested in heavy machinery for display, handling and functional play. Within the theme, it sits among large construction-vehicle models, where its appeal comes from the mechanical layout, licensed subject and strong shelf presence.

Inventory of set 42131

The inventory of set 42131 lists 3,854 pieces, spare parts excluded: 231 different lots (one shape in one color) for 175 part shapes. The box also contains 25 spare parts, for small elements that are easy to lose.

Colors of set 42131

Main color: black, making up 39% of the parts, followed by yellow (21%) and blue (15%).

Part types

Most common parts in set 42131

159 of the 175 part shapes in this set have their own page on Setopedia, with their colors, element numbers and the other sets that use them. See all LEGO parts

Exclusive parts in set 42131

2 part shapes in set 42131 appear in no other set in the catalog, most often printed elements, stickers or molds specific to the model. If one gets lost, you will need to look for it individually, for example on BrickLink, rather than in another set.

Rebuilding set 42131 from another set

Share of the parts of set 42131 found in each of these similarly sized sets, counting shape, colour and quantity:

No similarly sized set goes above 53%: the model relies on a little-shared assortment, most of which has to be gathered piece by piece.

Size of set 42131 within its line

With 3,854 pieces, set 42131 ranks #6 out of 443 Technic sets in our database, which have an average of 658 parts. Among the 519 sets released in 2021, it ranks #9. That is 5.9 times the average Technic set size.