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.
Cone 1 x 1 [Top Groove]BlackPart 59900Element 4529236×4
Technic Panels
4 pieces
Technic Panel Fairing #21 5L Small Smooth, Side BDark TanPart 11946Element 6593774 or 6352644×2
Technic Panel Fairing #22 5L Small Smooth, Side ADark TanPart 11947Element 6593776 or 6352663×2
Technic Beams Special
3 pieces
Technic Beam 3 x 0.5 Liftarm with Boss and Pin Semi-ReducedBlackPart 33299bElement 4563044×1
Technic Beam 1 x 3 with Ball Joint in MiddleDark Bluish GrayPart 98577Element 6001085×1
Technic Beam 5 x 5 x 2 Perpendicular Fork 3 FingersDark Bluish GrayPart 19086Element 6102645×1
Technic Beams
2 pieces
Technic Beam 1 x 2 Thick with Pin Hole and Axle HoleDark Bluish GrayPart 60483Element 6265093 or 6006141×1
Technic Beam 1 x 2 ThinDark Bluish GrayPart 41677Element 6338422 or 4210980×1
Technic Special
2 pieces
Technic Ball Joint with Through Axle HoleBlackPart 53585Element 4286267×2
Technic Bushes
1 piece
Technic Bush 1/2 Smooth with Axle Hole Semi-ReducedLight Bluish GrayPart 32123bElement 6271165 or 42115731 spare in the box×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.