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 Hub for Portal AxleDark Bluish GrayPart 92909Element 4610378×4
Tan
22 pieces
Technic Axle Connector Ridged [with x Hole x Orientation]TanPart 6538bElement 4207456 or 4140453×1
Technic Engine Crankshaft CenterTanPart 2854Element 6355727 or 6013937×3
Technic Gear 12 Tooth BevelTanPart 6589Element 4565452 or 45145561 spare in the box×9
Technic Gear 20 Tooth BevelTanPart 32198Element 6031962 or 4514557×1
Technic Pin Long without Friction RidgesTanPart 32556×8
Flat Silver
6 pieces
Hose, Ribbed 7mm D. 11L / 8.8cmFlat SilverPart 78c11Element 46174922 spares in the box×6
Trans-Clear
6 pieces
Plate Round 1 x 1 with Solid StudTrans-ClearPart 6141Element 6514052 or 62400301 spare in the box×6
Dark Tan
3 pieces
Technic Axle 3 with StudDark TanPart 6587Element 6031821 or 6013821×3
[No Color/Any Color]
2 pieces
Sticker Sheet 1 for Set 42000-1[No Color/Any Color]Part 13575Element 6030681×1
Sticker Sheet 2 for Set 42000-1[No Color/Any Color]Part 13576Element 6030682×1
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.