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 Pin with Friction Ridges Lengthwise and Center SlotsBlackPart 2780Element 4121715 or 2780261 spare in the box×1
Technic Axle Pin with Friction Ridges LengthwiseBluePart 43093Element 4309323 or 4206482×1
Technic Pin Long with Friction Ridges Lengthwise, 2 Center SlotsBluePart 6558Element 4514553×1
Projectiles / Launchers
2 pieces
Projectile, Large Figure Weapon, Zamor Sphere / BallBright GreenPart 54821×1
Launcher, Large Figure Weapon, Zamor Sphere Launcher, Bottom with Axle HoleOrangePart 98564Element 6021673 or 4653045×1
Technic Bushes
2 pieces
Technic BushRedPart 3713Element 6271820 or 42271551 spare in the box×2
Technic Connectors
2 pieces
Technic Axle Connector 2 x 3 with Ball Socket, Open Lower Axle HolesDark Bluish GrayPart 93571Element 6287965 or 4626667×2
Technic Beams
1 piece
Technic Beam 2 x 4 L-Shape ThickBlackPart 32140Element 6271825 or 4120017×1
Technic Special
1 piece
Technic Ball Joint with Through Axle HoleRedPart 53585Element 4615070 or 4543094×1
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.