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.
Builders who report a missing piece often find it in one of these places. Tick each one off as you look.
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 Beam 1 x 3 ThinBlack ×8Dark Bluish Gray ×8Black is darker than Dark Bluish Gray.
Technic Beam 1 x 4 ThinBlack ×6Dark Bluish Gray ×6Black is darker than Dark Bluish Gray.
Plate Special 1 x 2 with Pin Hole UnderneathLight Bluish GrayPart 18677Element 6168633 or 6089147×8
Tiles Round and Curved
8 pieces
Tile Round 1 x 1Trans-ClearPart 98138Element 6514191 or 62747381 spare in the box×5
Tile Round 1 x 1Trans-GreenPart 98138Element 6514194 or 62747421 spare in the box×1
Tile Round 1 x 1Trans-RedPart 98138Element 6514189 or 62586071 spare in the box×2
Plates Round Curved and Dishes
7 pieces
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening)Dark Bluish GrayPart 4032aElement 4211042×2
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening)OrangePart 4032aElement 6030521 or 4164243×1
Plate Round 2 x 2 with Rounded Bottom [Boat Stud]OrangePart 2654Element 6220710 or 4160636×1
Dish 8 x 8 Inverted [Radar], Solid Studs, Rounded Anti-stud UndersideRedPart 3961Element 6603363 or 6402243×1
Plate Round 1 x 1 with Solid StudTrans-ClearPart 6141Element 6514052 or 62400301 spare in the box×2
Bricks Special
6 pieces
Brick Special 1 x 1 with Stud on 1 SideWhitePart 87087Element 6550190 or 4558952×2
Brick Special 1 x 2 with 2 Studs on 1 SideWhitePart 11211Element 6550150 or 6058177×2
Brick Special 1 x 4 with 4 Studs on One SideWhitePart 30414Element 6550167 or 4143254×2
Bricks Curved
4 pieces
Brick Curved 2 x 2 x 2/3WhitePart 15068Element 6552147 or 6047220×2
Brick Curved Inverted 2 x 2 x 2/3WhitePart 32803Element 6210385×2
Transportation - Land
3 pieces
Steering Wheel Small, 2 x 2 [Reinforced]Light Bluish GrayPart 16091Element 6092956 or 6061697×1
Seat / Chair 2 x 2 with Center Sprue MarkWhitePart 4079bElement 407901×2
Bars, Ladders and Fences
2 pieces
Bar 5L with Handle (Friction Ram)BlackPart 87618Element 4623113×2
Bricks Round and Cones
2 pieces
Brick Round 2 x 2 D. Tube with 45° Elbow and Axle Holes (Crossholes) at Each End [SHORT]BlackPart 65473Element 6305216×2
Containers
2 pieces
Barrel 2 x 2 x 2Light Bluish GrayPart 2489Element 6278993 or 4218758×2
Electronics
2 pieces
Motor, Large, Powered UpDark Bluish GrayPart 22169Element 6545732 or 6456189×1
Hub, Powered Up 2-Port (Non-Bluetooth) - Screw OpeningLight Bluish GrayPart 85825Element 6603234 or 6375902×1
Stickers
2 pieces
Sticker Sheet 1 for Set 42145-1[No Color/Any Color]Part 10102495Element 6431135×1
Sticker Sheet 2 for Set 42145-1[No Color/Any Color]Part 10101351Element 6418451×1
String, Bands and Reels
2 pieces
String Cord Medium Thickness (1mm) 150cmDark Bluish GrayPart 37597c150Element 6431485 or 6226157×1
Technic Reel 3 x 2Dark Bluish GrayPart 32012Element 32012199 or 4239891×1
Supports, Girders and Cranes
2 pieces
Hook with TowballDark Bluish GrayPart 30395Element 30395199 or 6347464×2
Technic Bricks
2 pieces
Technic Brick 1 x 10 [9 Pin Holes]WhitePart 2730Element 273001×2
Large Buildable Figures
1 piece
Large Figure Weapon, Barrel with 2 Pin Holes and 3 Axle HolesBlackPart 98585Element 6186133 or 6156897×1
Tubes and Hoses
1 piece
Axle Hose, Soft 19LBlackPart 32235Element 6139205 or 4121650×1
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.
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.