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 Steering Wheel Pilot's Yoke [Open Stud, Axle Hole with X Opening]Dark Bluish GrayPart 40001Element 6023800 or 4210710×1
White
8 pieces
Brick Round 2 x 2 Dome Top, Blocked Open Stud, Bottom Axle HolderWhitePart 30367b×2
Brick Round 2 x 2 with Axle HoleWhitePart 3941Element 6601920 or 614351×4
Technic Axle and Pin Connector Perpendicular 3L with Centre Pin HoleWhitePart 32184Element 6276981 or 6114940×2
Pearl Light Gray
4 pieces
Hose, Ribbed 7mm D. 11L / 8.8cmPearl Light GrayPart 78c11Element 4495208 or 4141672×2
Technic Engine Tunable, Block with Trapezoidal Air ScoopPearl Light GrayPart 46453Element 4494989 or 4297957×2
Trans-Red
4 pieces
Technic Tooth 1 x 3 with Axle Hole [Rounded Underside]Trans-RedPart 41669Element 4163567×4
Trans-Clear
2 pieces
Plate Round 2 x 2 with Rounded Bottom [Boat Stud]Trans-ClearPart 2654Element 6581772 or 6163901×2
[No Color/Any Color]
1 piece
Sticker Sheet for Set 8146-1[No Color/Any Color]Part 57861Element 4496163×1
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.