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.
LEGO counts 410 pieces. This inventory comes from a separate parts catalog and lists 412; the two do not always count the same elements, so their totals differ. Spare parts are counted in neither figure.
Before you call it missing
Builders who report a missing piece often find it in one of these places. Tick each one off as you look.
Look-alike colors in this set
These parts appear in this set in two colors that are easy to confuse. If you are one short in one color,
check whether it went in where the other color belongs. Each color has its own element ID in the parts list
at the back of the instructions.
Brick 1 x 3Black ×2Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Brick Round Corner 4 x 4 Macaroni Wide with 3 StudsBlack ×4Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Brick Sloped 75° 2 x 1 x 3 with Open StudBlack ×8Dark Bluish Gray ×4Black is darker than Dark Bluish Gray.
Launcher, Technic Competition Cannon, Round Bottom with Same Color EndsBlack ×1Dark Bluish Gray ×1Black is darker than Dark Bluish Gray.
Plate 1 x 2Black ×7Dark Bluish Gray ×5Black is darker than Dark Bluish Gray.
Plate 1 x 4Black ×4Dark Bluish Gray ×3Black is darker than Dark Bluish Gray.
1 more look-alike pair
Plate 2 x 2 CornerBlack ×4Dark Bluish Gray ×12Black is darker than Dark Bluish Gray.
Launcher, Technic Competition Cannon, Round Bottom with Same Color EndsDark Bluish GrayPart 32074c01Element 4221095Also in Black×1
Projectile, Technic Competition Arrow, Beam Shaft with Solid Black Rubber EndLight Bluish GrayPart 76110c01Element 4225060×1
Supports, Girders and Cranes
4 pieces
Support Round 1 x 1 x 6 Solid PillarDark Bluish GrayPart 43888Element 4180811×4
Bars, Ladders and Fences
3 pieces
Bar 7 x 3 with Double Clips (Ladder) [Straight Clips]Light Bluish GrayPart 6020Element 4275673×3
Bricks Curved
2 pieces
Brick Arch 1 x 6Dark Bluish GrayPart 3455Element 4211123×2
Rock
2 pieces
Rock Boulder 4 x 4, Bottom with Marbled Trans-Neon Orange PatternDark Bluish GrayPart 30294pat0001Element 4288141×1
Rock Boulder 4 x 4, Top with Marbled Trans-Neon Orange PatternDark Bluish GrayPart 30293pat0001Element 4285879×1
String, Bands and Reels
2 pieces
String Cord Medium Thickness 40cmGreenPart 14728c40×2
Technic Bushes
2 pieces
Technic Bush 1/2 Smooth with Axle Hole Semi-ReducedLight Bluish GrayPart 32123bElement 6271165 or 42115731 spare in the box×2
Tiles
2 pieces
Tile 1 x 4 with GrooveDark Bluish GrayPart 2431Element 4211053×2
Stickers
1 piece
Sticker Sheet for Set 8758-1[No Color/Any Color]Part 54205Element 4277465×1
Technic Beams Special
1 piece
Technic Beam 1 x 2 with Ball Joint AngledDark Bluish GrayPart 50923Element 4503381 or 4289258×1
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.