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.
Technic Gear 16 Tooth with Round Holes [Old Style]Light Bluish GrayPart 4019Element 4562487 or 4211563×1
Technic Gear 20 Tooth Double Bevel with Axle Hole Type 2 [X Opening]Light Bluish GrayPart 32269Element 32269194 or 4211635×2
Technic Gear 8 ToothLight Bluish GrayPart 3647Element 4211432 or 36471941 spare in the box×1
Technic Bricks
14 pieces
Technic Brick 1 x 2 [2 Pin Holes]BlackPart 32000Element 3200026×12
Technic Pin Connector Block 1 x 5 x 3Light Bluish GrayPart 32333Element 6271360 or 4205761×2
Technic Bushes
14 pieces
Technic BushLight Bluish GrayPart 3713Element 6275844 or 62718171 spare in the box×9
Technic Bush 1/2 Smooth with Axle Hole Semi-ReducedLight Bluish GrayPart 32123bElement 6271165 or 42115731 spare in the box×5
Plates
9 pieces
Plate 1 x 4BlackPart 3710Element 371026×1
Plate 2 x 10BlackPart 3832Element 383226×1
Plate 2 x 2BlackPart 3022Element 302226×2
Plate 2 x 3BlackPart 3021Element 302126×2
Plate 2 x 4BlackPart 3020Element 302026×3
Bricks Sloped
8 pieces
Brick Sloped 33° 3 x 2BlackPart 3298Element 329826×2
Brick Sloped 45° 2 x 1 with Bottom PinBlackPart 3040bElement 4121966 or 304026×2
Brick Sloped 45° 2 x 2 Double ConvexBlackPart 3045Element 4189064 or 304526×2
Brick Sloped 45° 2 x 3BlackPart 3038Element 303826×2
Wheels and Tyres
8 pieces
Tyre 81.8 x 50 Technic Racing LargeBlackPart 32296Element 4294850×4
Wheel 62 x 46 Technic Racing LargeMetallic SilverPart 56424Element 4294868 or 4141516×4
Tiles
5 pieces
Tile 1 x 2 with GrooveRedPart 3069bElement 4178178 or 306921×1
Tile 1 x 8 with GrooveRedPart 4162Element 416221×2
Tile 1 x 6 with GrooveWhitePart 6636Element 6548296 or 663601×2
Plates Special
4 pieces
Plate Special 4 x 4, Studs on One Edge Plain]RedPart 6179Element 4616342 or 4129831×2
Plate Special 4 x 6, Studs on 3 EdgesRedPart 6180Element 6315022 or 4624534×2
Technic Beams Special
4 pieces
Technic Beam 3 x 0.5 Liftarm with Boss and Pin / CrankBlackPart 33299aElement 4156980×4
Technic Special
4 pieces
Technic Tooth 1 x 3 with Axle Hole [Rounded Underside]RedPart 41669Element 4185661×4
Bars, Ladders and Fences
1 piece
Bar 6.6L with Stop Ring [Umbrella Stand]WhitePart 4095Element 4294998 or 409551×1
Bricks Curved
1 piece
Brick Curved 6 x 2BlackPart 44126Element 4180548×1
Stickers
1 piece
Sticker Sheet for Set 8674-1[No Color/Any Color]Part 56406Element 4294702×1
Tiles Special
1 piece
Tile Special 1 x 2 Grille with Bottom GrooveTrans-RedPart 2412bElement 6250158 or 4190187×1
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.