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 Beam 1 x 15 ThickBlackPart 32278Element 4542573 or 4128603×1
Technic Beam 1 x 9 Bent (7 - 3) ThickBlackPart 32271Element 6276835 or 4140327×3
Technic Beam 1 x 9 ThickBlackPart 40490Element 4645732 or 4542788×2
Technic Beam 1 x 2 ThinLight Bluish GrayPart 41677Element 6348143 or 4211741×6
Technic Beam 1 x 3 ThinLight Bluish GrayPart 6632Element 6360043 or 4211566×2
Technic Beam 1 x 6 ThinLight Bluish GrayPart 32063Element 6170293 or 4211586×1
Projectiles / Launchers
10 pieces
Launcher, Large Figure Weapon Cannon, Cordak BlasterPearl Light GrayPart 57523c01Element 4544505 or 4504505×1
Projectile, Large Figure Weapon, Ammo (Cordak)RedPart 57525Element 44977961 spare in the box×9
Tubes and Hoses
4 pieces
Flexible Ribbed Hose 8mm Ends 19LBlackPart 57539Element 4561467 or 4504612×1
Axle Hose, Soft 7LPearl Light GrayPart 32580Element 4287618 or 4163389×3
Technic Bushes
2 pieces
Technic BushLight Bluish GrayPart 3713Element 6275844 or 62718171 spare in the box×2
Technic Special
2 pieces
Technic Tooth 1 x 3 with Axle Hole [Rounded Underside]Pearl Light GrayPart 41669Element 4284480 or 4177440×2
Transportation - Sea and Air
2 pieces
Jet Engine Fan with 10 Blades and Technic PinBlackPart 46667Element 6313481 or 6088638×2
Wheels and Tyres
2 pieces
Wheel 18 x 14 with Pin Hole, Fake Bolts and Shallow SpokesLight Bluish GrayPart 55981Element 6109684 or 42991191 spare in the box×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.