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LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

Checking

42242 Mercedes-Benz Unimog U 5023 with Crane

1,189 pieces in 220 part and color combinations.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

Every bag and the box. Shake out each bag, check its corners and seams, and look inside the empty box.
Inside what you have built. Small pieces lodge inside tubes, under plates and between studs. Turn the model over and look.
The last few steps. Compare each recent step with its parts callout. A piece used in the wrong place earlier leaves you one short later.
Look-alike colors. 6 parts in this set come in two colors that are easy to mix up; they are listed below.
The spare pieces. This set comes with 22 spare pieces, marked on each row of the checklist. One may be the piece you need.
The floor and your building area. Check under furniture, the chair and the edges of your building surface.

Look-alike colors in this set

These parts appear in this set in two colors that are easy to confuse. If you are one short in one color, check whether it went in where the other color belongs. Each color has its own element ID in the parts list at the back of the instructions.

Technic Axle Connector Smooth [with x Hole + Orientation] Black ×3 Dark Bluish Gray ×12 Black is darker than Dark Bluish Gray.
Technic Axle and Pin Connector Perpendicular Black ×10 Dark Bluish Gray ×2 Black is darker than Dark Bluish Gray.
Technic Beam 1 x 3 Thick Black ×14 Dark Bluish Gray ×4 Black is darker than Dark Bluish Gray.
Technic Beam 1 x 5 Thick Black ×2 Dark Bluish Gray ×2 Black is darker than Dark Bluish Gray.
Technic Beam 2 x 3 L-Shape with Quarter Ellipse Thick Black ×2 Dark Bluish Gray ×2 Black is darker than Dark Bluish Gray.
Technic Pin Connector Round 1L [Beam] Black ×4 Dark Bluish Gray ×4 Black is darker than Dark Bluish Gray.

Piece checklist

Technic Bushes 43 pieces

Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced Light Bluish Gray Part 32123b Element 6271165 or 4211573 2 spares in the box ×20
Technic Bush Red Part 3713 Element 6271820 or 4227155 3 spares in the box ×23

Tiles 14 pieces

Tile 1 x 4 with Groove Black Part 2431 Element 243126 ×1
Tile 1 x 6 with Groove Black Part 6636 Element 663626 ×2
Tile 2 x 3 Black Part 26603 Element 6162892 ×3
Tile 1 x 4 with Groove Trans-Clear Part 2431 Element 6510182 or 6289455 ×2
Tile 1 x 1 with Groove Trans-Orange Part 3070b Element 6514258 or 6254252 1 spare in the box ×4
Tile 1 x 2 with Groove Trans-Red Part 3069b Element 6514220 or 6251290 ×2

Wheels and Tyres 12 pieces

Technic Wedge Belt Wheel [aka Pulley] Black Part 4185 Element 6323668 or 6192130 ×4
Tyre 56 x 26 Tractor Black Part 70695 Element 6325260 ×4
Wheel 30.4 x 20 without Pinholes, with Reinforced Rim Black Part 56145 Element 4299389 or 4284946 ×4

Tubes and Hoses 9 pieces

Hose, Pneumatic 4mm D. 19L / 15.2cm Black Part 5102c19 Element 6587918 ×3
Hose, Pneumatic 4mm D. 2L / 1.6cm Blue Part 5102c02 Element 6587913 or 6352204 ×1
Hose, Pneumatic 4mm D. 8L / 6.4cm Blue Part 5102c08 Element 6587915 or 4563299 ×1
Hose, Pneumatic 4mm D. 14L / 11.2cm Light Bluish Gray Part 5102c14 Element 6587916 or 6218208 ×2
Hose, Pneumatic 4mm D. 19L / 15.2cm Light Bluish Gray Part 5102c19 Element 6587919 or 6119485 ×1
Hose, Pneumatic 4mm D. 3L / 2.4cm Light Bluish Gray Part 5102c03 Element 6587914 ×1

Pneumatics 8 pieces

Pneumatic Pump Large (11L) with 1 x 3 Liftarm Blue Part 26288 Element 6353193 or 6152004 ×1
Pneumatic Cylinder 2 x 11 with 2 Stepped Inlets [V2] Dark Bluish Gray Part 19478 Element 6383181 ×2
Pneumatic Hose Connector with Axle Connector Dark Bluish Gray Part 99021 Element 6265669 or 6020189 ×2
Pneumatic Switch with Pin Holes, Axle Hole and Stepped Outlets Light Bluish Gray Part 19474 Element 6099773 ×2
Pneumatic T-Piece (T Bar) [New Style] Light Bluish Gray Part 4697b Element 4211508 1 spare in the box ×1

Plates Special 7 pieces

Plate Special 2 x 2 with 1 Pin Hole [Complete Underside Rib] Black Part 10247 Element 6061032 ×2
Plate Special 2 x 2 with 2 Pins Dark Bluish Gray Part 15092 Element 6284702 or 6066952 ×1
Plate Special 1 x 2 with Pin Hole Underneath Light Bluish Gray Part 18677 Element 6168633 or 6089147 ×4

Technic Beams Special 6 pieces

Technic Beam Frame 5 x 7 with 3 x 5 Opening Thick Black Part 64179 Element 6016154 ×1
Technic Beam 1 x 2 with Towball Straight Light Bluish Gray Part 5995 Element 6506199 ×1
Technic Beam 3 x 0.5 Liftarm with Boss and Blocked, Squared Pin Hole Light Bluish Gray Part 61408 Element 6331859 ×2
Technic Beam 3 x 5 Thick [90° Offset Centre Beam Holes] Red Part 14720 Element 6534281 or 6185105 ×2

Tiles Round and Curved 6 pieces

Tile Round 1 x 1 Trans-Clear Part 98138 Element 6514191 or 6274738 1 spare in the box ×4
Tile Round 1 x 1 Trans-Orange Part 98138 Element 6514197 or 6274747 1 spare in the box ×2

Plates 5 pieces

Plate 1 x 10 Black Part 4477 Element 447726 ×1
Plate 1 x 4 Black Part 3710 Element 371026 ×1
Plate 1 x 6 Black Part 3666 Element 366626 ×1
Plate 2 x 4 Black Part 3020 Element 302026 ×1
Plate 1 x 2 Dark Bluish Gray Part 3023 Element 4211063 ×1

Technic Bricks 5 pieces

Technic Brick 1 x 12 [11 Pin Holes] Black Part 3895 Element 389526 ×1
Technic Brick 1 x 2 [1 Pin Hole] Black Part 3700 Element 370026 ×2
Technic Brick 1 x 2 [2 Pin Holes] Black Part 32000 Element 3200026 ×2

Bars, Ladders and Fences 2 pieces

Bar 3L Light Bluish Gray Part 87994 Element 6093527 or 6064033 1 spare in the box ×1
Bar 1L with Clip [Cut Edges and One Side Hole] [Full Clip] Yellow Part 3484 Element 6439051 ×1

Bricks Round and Cones 2 pieces

Brick Round 1 x 1 diameter Tube with 90 Degree Elbow (2 x 2 x 1) and Axle Holes (Crossholes) at each end Light Bluish Gray Part 25214 Element 6151349 ×2

Hinges, Arms and Turntables 2 pieces

Hinge 1 x 2 Locking with 2 Fingers and Towball Socket, 7 Teeth Black Part 51482 Element 6266320 ×1
Hinge Cylinder 1 x 2 Locking with 1 Finger and Axle Hole On Ends [No Side Slots] Light Bluish Gray Part 53923 Element 6265704 ×1

Plates Round Curved and Dishes 2 pieces

Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Black Part 4032a Element 403226 ×1
Plate Round 2 x 2 with Rounded Bottom [Boat Stud] Black Part 2654 Element 4617551 or 4278359 ×1

Minifig Shields, Weapons, & Tools 1 piece

Shield Round Bowed with Silver Mercedes-Benz Logo Black Part 75902pr9997 Element 6463325 ×1

Stickers 1 piece

Sticker Sheet for Set 42242-1 [No Color/Any Color] Part 10116865 Element 6599539 ×1

Supports, Girders and Cranes 1 piece

Hook with Towball Dark Bluish Gray Part 30395 Element 30395199 or 6347464 ×1

Tiles Special 1 piece

Tile Special Round 2 x 2 with Hole Black Part 15535 Element 6143850 ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.

LEGO Missing Piece Checker

42242 Mercedes-Benz Unimog U 5023 with Crane

Before you call it missing

Look-alike colors in this set

Your missing list

Piece checklist

Technic Pins 384 pieces

Technic Beams 270 pieces

Technic Connectors 189 pieces