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 Axle 3 with StopReddish BrownPart 24316Element 6135494×3
Technic Beams
6 pieces
Technic Beam 1 x 4 ThinBlackPart 32449Element 6327548 or 4142236×2
Technic Beam 1 x 2 ThinDark Bluish GrayPart 41677Element 6338422 or 4210980×4
Technic Beams Special
6 pieces
Technic Beam 1 x 2 with Ball Joint Straight, Smooth BallBlackPart 64276Element 4560108 or 4537514×4
Technic Beam 1 x 2 with Ball Joint AngledDark Bluish GrayPart 50923Element 4503381 or 4289258×2
Technic Bushes
3 pieces
Technic BushLight Bluish GrayPart 3713Element 6275844 or 6271817×1
Technic Bush 1/2 Smooth with Axle Hole Semi-ReducedLight Bluish GrayPart 32123bElement 6271165 or 4211573×2
Pneumatics
2 pieces
Pneumatic Hose Connector with Axle ConnectorDark Bluish GrayPart 99021Element 6265669 or 6020189×2
Technic Special
2 pieces
Technic Tooth 1 x 3 with Axle Hole [Rounded Underside]Trans-Neon GreenPart 41669Element 4163577×2
Technic Steering, Suspension and Engine
2 pieces
Technic Link 1 x 9BlackPart 32293Element 6244698 or 4141300×2
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.