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.
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.
Technic Panel Fairing #21 5L Small Smooth, Side BBlack ×1Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Panel Fairing #22 5L Small Smooth, Side ABlack ×3Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Panel Fairing #7 3L Very Small Smooth, Side ABlack ×6Dark Bluish Gray ×3Black is darker than Dark Bluish Gray.
Technic Panel Fairing #8 3L Very Small Smooth, Side BBlack ×6Dark Bluish Gray ×3Black is darker than Dark Bluish Gray.
Technic Beam 1 x 11.5 Double Bent ThickBright GreenPart 32009Element 6468846×2
Technic Beam 1 x 2 ThickBright GreenPart 43857Element 6316318×1
Technic Beam 1 x 9 Bent (6 - 4) ThickBright GreenPart 6629Element 6476570×2
Technic Beam 2 x 3 L-Shape with Quarter Ellipse ThickBright GreenPart 71708Element 6478283×2
Technic Beam 2 x 4 L-Shape ThickBright GreenPart 32140Element 6476572×1
Technic Beam 3 x 5 L-Shape ThickBright GreenPart 32526Element 6097397×2
Technic Pin Connector Hub with 1 AxleBright GreenPart 22961Element 6476580×2
Tile Round 1 x 1Bright GreenPart 98138Element 63537931 spare in the box×2
Reddish Brown
6 pieces
Technic Axle 3 with StopReddish BrownPart 24316Element 6135494×1
Technic Axle 5 with StopReddish BrownPart 15462Element 6159763×5
Dark Tan
4 pieces
Technic Axle 3 with StudDark TanPart 6587Element 6031821 or 6013821×4
Tan
3 pieces
Technic Axle Pin without Friction Ridges LengthwiseTanPart 3749Element 4666579 or 4186017×1
Technic Pin 3/4TanPart 32002Element 6663097 or 60139381 spare in the box×2
Trans-Red
2 pieces
Technic Tooth 1 x 3 with Axle Hole [Hollow Underside]Trans-RedPart 48267Element 6514318 or 6275769×2
Green
1 piece
Technic Gear 20 Tooth with Clutch on Both SidesGreenPart 81346Element 6391159×1
Orange
1 piece
Gear ShifterOrangePart 35188Element 6227330×1
Pearl Gold
1 piece
Technic Pin Connector Round 1L [Beam]Pearl GoldPart 18654Element 62568031 spare in the box×1
Trans-Clear
1 piece
Windscreen 7 x 6 1/2 x 2 Motorcycle with Black Border PrintTrans-ClearPart 5401pr0001Element 6661102 or 6480502×1
[No Color/Any Color]
1 piece
Sticker Sheet for Set 42170-1[No Color/Any Color]Part 10105326Element 6462839×1
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.