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 Axle and Pin Connector Angled #3 - 157.5°RedPart 32016Element 6261396 or 6176754×2
Technic Beam 2 x 4 L-Shape ThickRedPart 32140Element 6271827 or 4141270×2
Blue
7 pieces
Technic Axle Pin with Friction Ridges LengthwiseBluePart 43093Element 4309323 or 4206482×6
Technic Rubber Belt Medium [26mm ID] [Round Cross Section]BluePart 85545Element 6049730 or 4544147×1
Trans-Clear
6 pieces
Plate Round 1 x 1 with Solid StudTrans-ClearPart 6141Element 6514052 or 62400301 spare in the box×6
Metallic Silver
3 pieces
Engine / Air Scoop 2 x 2Metallic SilverPart 50943Element 6051377 or 4579841×1
Tile Special 1 x 2 Grille with Bottom GrooveMetallic SilverPart 2412bElement 6051422 or 4579833×2
Tan
3 pieces
Technic Axle Pin without Friction Ridges LengthwiseTanPart 3749Element 4666579 or 4186017×3
Pearl Light Gray
2 pieces
Hose, Ribbed 7mm D. 5L / 4.0cmPearl Light GrayPart 78c05Element 4495201 or 4275382×2
Trans-Orange
2 pieces
Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope)Trans-OrangePart 54200Element 6245265 or 4244369×2
[No Color/Any Color]
1 piece
Sticker Sheet for Set 8141-1[No Color/Any Color]Part 57856Element 4496158×1
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.