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 Axle Connector Smooth [with x Hole + Orientation]Black ×27Dark Bluish Gray ×9Black is darker than Dark Bluish Gray.
Technic Axle and Pin Connector PerpendicularBlack ×15Dark Bluish Gray ×7Black is darker than Dark Bluish Gray.
Technic Axle and Pin Connector Perpendicular 3L with 2 Pin HolesBlack ×2Dark Bluish Gray ×15Black is darker than Dark Bluish Gray.
Technic Beam 1 x 11 ThickBlack ×5Dark Bluish Gray ×3Black is darker than Dark Bluish Gray.
Technic Beam 1 x 13 ThickBlack ×1Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Beam 1 x 2 Thick with Pin Hole and Axle HoleBlack ×57Dark Bluish Gray ×6Black is darker than Dark Bluish Gray.
13 more look-alike pairs
Technic Beam 1 x 3 ThickBlack ×17Dark Bluish Gray ×8Black is darker than Dark Bluish Gray.
Technic Beam 1 x 5 ThickBlack ×8Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Beam 1 x 5 Thin with Axle Holes on EndsBlack ×9Dark Bluish Gray ×4Black is darker than Dark Bluish Gray.
Technic Beam 1 x 7 ThickBlack ×13Dark Bluish Gray ×8Black is darker than Dark Bluish Gray.
Technic Beam 2 x 4 L-Shape ThickBlack ×15Dark Bluish Gray ×17Black is darker than Dark Bluish Gray.
Technic Beam 3 x 5 L-Shape ThickBlack ×22Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Panel 5 x 11 x 1Black ×3Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Panel Fairing #7 3L Very Small Smooth, Side ABlack ×1Dark Bluish Gray ×1Black is darker than Dark Bluish Gray.
Technic Panel Fairing #8 3L Very Small Smooth, Side BBlack ×1Dark Bluish Gray ×1Black is darker than Dark Bluish Gray.
Technic Pin Connector Hub with 1 AxleBlack ×6Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Pin Connector Hub with 1 Pin with Friction Ridges Lengthwise [Centered Friction Ridge]Black ×14Dark Bluish Gray ×22Black is darker than Dark Bluish Gray.
Technic Pin Connector Hub with 2 Perpendicular AxlesBlack ×2Dark Bluish Gray ×2Black is darker than Dark Bluish Gray.
Technic Pin Connector Round 1L [Beam]Black ×55Dark Bluish Gray ×7Black is darker than Dark Bluish Gray.
Technic Axle Connector Smooth [with x Hole + Orientation]BlackPart 59443Element 6084612 or 4512363Also in Dark Bluish Gray×27
Technic Axle Connector with Axle Hole [Reinforced]BlackPart 42135Element 6331716×7
Technic Axle Pin 3L with Friction Ridges Lengthwise and 2L AxleBlackPart 18651Element 6089119×21
Technic Axle and Pin Connector Angled #1BlackPart 32013Element 6284699 or 4107085×6
Technic Axle and Pin Connector Angled #2 - 180°BlackPart 32034Element 6271869 or 4107783×7
Technic Axle and Pin Connector Angled #3 - 157.5°BlackPart 32016Element 6261386 or 4107082×6
Technic Axle and Pin Connector Angled #4 - 135°BlackPart 32192Element 6262897 or 4121610×8
Technic Axle and Pin Connector Angled #6 - 90°BlackPart 32014Element 6268905 or 4107767×6
Technic Axle and Pin Connector PerpendicularBlackPart 6536Element 6261371 or 4173668Also in Dark Bluish Gray×15
Technic Axle and Pin Connector Perpendicular 3L with 2 Pin HolesBlackPart 42003Element 6273708 or 4200326Also in Dark Bluish Gray×2
Technic Axle and Pin Connector Perpendicular 3L with Centre Pin HoleBlackPart 32184Element 6276951 or 4121667×8
Technic Axle and Pin Connector Perpendicular TripleBlackPart 63869Element 6362991 or 6007966×7
Technic Axle and Pin Connector Toggle Joint SmoothBlackPart 32126Element 6457112 or 6322045×4
Technic Ball JointBlackPart 32474Element 4290713 or 4143539×1
Technic Beam 1 x 11 ThickBlackPart 32525Element 6029578 or 4534909Also in Dark Bluish Gray×5
Technic Beam 1 x 11 Thick with Alternating HolesBlackPart 73507Element 6330585×4
Technic Beam 1 x 11.5 Double Bent ThickBlackPart 32009Element 6271152 or 4111998×8
Technic Beam 1 x 13 ThickBlackPart 41239Element 4522933 or 4164422Also in Dark Bluish Gray×1
Technic Beam 1 x 15 ThickBlackPart 32278Element 4542573 or 4128603×7
Technic Beam 1 x 15 Thick with Alternating HolesBlackPart 71710Element 6321716×6
Technic Beam 1 x 2 ThickBlackPart 43857Element 4385726 or 4177444×2
Technic Beam 1 x 2 Thick with Pin Hole and Axle HoleBlackPart 60483Element 6265091 or 6006140Also in Dark Bluish Gray×57
Technic Beam 1 x 2 ThinBlackPart 41677Element 6338428 or 4167726×11
Technic Beam 1 x 3 ThickBlackPart 32523Element 4142822 or 3252326Also in Dark Bluish Gray×17
Technic Beam 1 x 3 ThinBlackPart 6632Element 6331723 or 4107828×21
Technic Beam 1 x 4 ThinBlackPart 32449Element 6327548 or 4142236×12
Technic Beam 1 x 4 Thin with Stud ConnectorBlackPart 2825Element 6331570 or 4107136×5
Technic Beam 1 x 5 ThickBlackPart 32316Element 4142135 or 4140429Also in Dark Bluish Gray×8
Technic Beam 1 x 5 Thin with Axle Holes on EndsBlackPart 11478Element 6327028 or 6030286Also in Dark Bluish Gray×9
Technic Beam 1 x 7 Bent (4 - 4) ThickBlackPart 32348Element 6278125 or 4128593×2
Technic Beam 1 x 7 ThickBlackPart 32524Element 4495935 or 4155458Also in Dark Bluish Gray×13
Technic Beam 1 x 7 ThinBlackPart 32065Element 6271573 or 6253293×1
Technic Beam 1 x 9 Bent (6 - 4) ThickBlackPart 6629Element 6279881 or 4119800×10
Technic Beam 1 x 9 ThickBlackPart 40490Element 4645732 or 4542788×12
Technic Beam 2 x 3 L-Shape with Quarter Ellipse ThickBlackPart 71708Element 6326047×2
Technic Beam 2 x 4 L-Shape ThickBlackPart 32140Element 6271825 or 4120017Also in Dark Bluish Gray×15
Technic Beam 3 x 3 L-Shape ThinBlackPart 32056Element 6271810 or 4112287×8
Technic Beam 3 x 3 T-Shape ThickBlackPart 60484Element 4552347 or 4535771×13
Technic Beam 3 x 5 L-Shape ThickBlackPart 32526Element 4142823 or 3252626Also in Dark Bluish Gray×22
Technic Beam 3 x 5 L-Shape Thick with Alternating HolesBlackPart 2477Element 6408182×4
Technic Beam Frame 11 x 15BlackPart 39790Element 6295161×1
Technic Beam Frame 3 x 19 with 2 Center Cross Beams, 3 Openings ThickBlackPart 67491Element 6377025×2
Technic Beam Frame 7 x 11BlackPart 39794Element 6265643×2
Technic Brick 1 x 1 with Axle HoleBlackPart 73230Element 6344819×5
Technic Brick 1 x 1 with Pin HoleBlackPart 6541Element 654126×2
Technic Brick 1 x 12 [11 Pin Holes]BlackPart 3895Element 389526×1
Technic Brick 1 x 2 [2 Pin Holes]BlackPart 32000Element 3200026×12
Technic Connector Beam 3 x 3BlackPart 39793Element 6265644×2
Technic Driving Ring Connector Smooth [2 rounded and 2 flat side walls]BlackPart 42195Element 6286381×8
Technic Gear 20 Tooth Double Bevel with Axle Hole Type 1 [+ Opening]BlackPart 18575Element 6346535 or 6093977×1
Technic Gear Rack 1 x 7 with Axle and Pin HolesBlackPart 87761Element 6327430 or 4562009×1
Technic Link 1 x 9BlackPart 32293Element 6244698 or 4141300×1
Technic Panel 3 x 11 x 1BlackPart 15458Element 6080356×3
Technic Panel 3 x 7 x 1BlackPart 71709Element 6331935×7
Technic Panel 5 x 11 x 1BlackPart 64782Element 4566243Also in Dark Bluish Gray×3
Technic Panel Curved 11 x 3 with 2 Pin Holes through Panel SurfaceBlackPart 62531Element 6214731 or 4530578×1
Technic Panel Curved 7 x 3 with 2 Pin Holes through Panel SurfaceBlackPart 24119Element 6150082×2
Technic Panel Fairing #7 3L Very Small Smooth, Side ABlackPart 2387Element 6510991 or 6426589Also in Dark Bluish Gray×1
Technic Panel Fairing #8 3L Very Small Smooth, Side BBlackPart 2389Element 6513874 or 6426590Also in Dark Bluish Gray×1
Technic Panel Fairing 2 x 1 x 1BlackPart 89679Element 6396456×2
Technic Panel Fairing 2 x 3 x 1BlackPart 71682Element 6331026×12
Technic Pin Connector Hub with 1 AxleBlackPart 22961Element 6253260Also in Dark Bluish Gray×6
Technic Pin Connector Hub with 1 Pin with Friction Ridges Lengthwise [Centered Friction Ridge]BlackPart 65487Element 6282140Also in Dark Bluish Gray×14
Technic Pin Connector Hub with 2 Perpendicular AxlesBlackPart 10197Element 6099801 or 6098801Also in Dark Bluish Gray×2
Technic Pin Connector Hub with 2 Pins with Friction Ridges Lengthwise [Small Squared Pin Holes]BlackPart 44874Element 6366229×6
Technic Driving Ring Connector Smooth [2 rounded and 2 flat side walls]GreenPart 42195Element 6443225×1
Technic Gear 12 Tooth with Clutch on One SideGreenPart 3590Element 6434577×1
Technic Gear 20 Tooth with Clutch on Both SidesGreenPart 81346Element 6391159×1
Bright Green
2 pieces
Bar 3LBright GreenPart 87994Element 61617721 spare in the box×2
Dark Tan
2 pieces
Technic Axle 3 with StudDark TanPart 6587Element 6031821 or 6013821×2
Orange
1 piece
Gear Shifter ForkOrangePart 4159Element 6447082×1
[No Color/Any Color]
1 piece
Sticker Sheet for Set 42177-1[No Color/Any Color]Part 10105333Element 6462846×1
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.