BlockTalk Find Your Set

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LEGO Missing Piece Checker

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.

Cities and Transportation

Checking

9723 Cities and Transportation

394 pieces in 114 part and color combinations.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

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Piece checklist

Black 124 pieces

  • Bracket 2 x 2 - 2 x 2 Black Part 3956 Element 6254808 or 6019217 ×2
  • Brick 1 x 2 Black Part 3004 Element 300426 ×4
  • Brick 2 x 2 Black Part 3003 Element 4103587 or 300326 ×4
  • Brick Round 2 x 2 with Axle Hole Black Part 3941 Element 614376 or 614326 ×8
  • Hair Center Parting Black Part 4530 Element 4659663 or 453026 ×1
  • Hair Smooth Black Part 3901 Element 390176 or 390126 ×1
  • Hips and Black Legs Black Part 970c03 Element 4569093 or 73407 ×1
  • Motor, 9V Mini [Lightweight New Style] Black Part 43362c01 ×1
  • Plate Round 2 x 2 with Rounded Bottom [Boat Stud] Black Part 2654 Element 4617551 or 4278359 ×2
  • Rubber Band Small 13mm (Square Cross Section) Black Part 71509 Element 4141606 or 4107153 ×4
  • Storage Bin, Dacta, Small Black Part upn0032 ×1
  • Technic Axle 10 Black Part 3737 Element 373726 ×2
  • Technic Axle 12 Black Part 3708 Element 370826 ×2
  • Technic Axle 2 Notched Black Part 32062 Element 4109810 or 3206226 ×4
  • Technic Axle 3 Black Part 4519 Element 6238084 or 451926 ×2
  • Technic Axle 4 Black Part 3705 Element 370526 ×2
  • Technic Axle 5 Black Part 32073 Element 4114740 ×2
  • Technic Axle 6 Black Part 3706 Element 370626 ×2
  • Technic Axle 8 Black Part 3707 Element 370726 ×2
  • Technic Brick 1 x 10 [9 Pin Holes] Black Part 2730 Element 273026 ×4
  • Technic Brick 1 x 12 [11 Pin Holes] Black Part 3895 Element 389526 ×4
  • Technic Brick 1 x 16 [15 Pin Holes] Black Part 3703 Element 370326 ×5
  • Technic Brick 1 x 2 [1 Pin Hole] Black Part 3700 Element 370026 ×16
  • Technic Brick 1 x 4 [3 Pin Holes] Black Part 3701 Element 370126 ×8
  • Technic Brick 1 x 6 [5 Pin Holes] Black Part 3894 Element 389426 ×4
  • Technic Brick 1 x 8 [7 Pin Holes] Black Part 3702 Element 370226 ×4
  • Technic Pin with Friction Ridges Lengthwise and Center Slots Black Part 2780 Element 4121715 or 278026 1 spare in the box ×12
  • Technic Wedge Belt Wheel Tire Black Part 2815 Element 6028041 or 281526 ×2
  • Technic Worm Gear Black Part 4716 Element 6037533 or 471626 ×4
  • Tyre 30 x 10.5 Offset Tread Black Part 2346 Element 234676 or 234626 ×2
  • Tyre 30.4 x 14 VR Black Part 6578 Element 4561806 or 657826 ×2
  • Tyre 43 x 17 Black Part 3634 Element 4523564 or 363426 ×2
  • Tyre Offset Tread 24 x 8 Black Part 3483 Element 4501048 or 348326 ×2
  • Wire with Brick 2 x 2 x 2/3 Pair, 20L Black Part 5306bc020 Element 4100355 ×2
  • Wire with Brick 2 x 2 x 2/3 Pair, 36L Black Part 5306bc036 Element 75652 ×2
  • Wire with Brick 2 x 2 x 2/3 Pair, 378L Black Part 5306bc378 Element 4110080 ×1
  • Wire with Brick 2 x 2 x 2/3 Pair, 69L Black Part 5306bc069 Element 75782 ×1

Light Gray 105 pieces

  • Motor Pulley, 9V Micromotor with axle hole Light Gray Part 2983 Element 298630 ×4
  • Sensor, Touch Light Gray Part 879 Element 4247135 or 4209116 ×2
  • Technic Axle Connector Ridged [with x Hole x Orientation] Light Gray Part 6538b Element 4113804 or 4100408 ×2
  • Technic Axle Pin without Friction Ridges Lengthwise Light Gray Part 3749 Element 4184168 or 4154179 ×8
  • Technic Axle and Pin Connector Angled #2 - 180° Light Gray Part 32034 Element 4107830 ×2
  • Technic Axle and Pin Connector Angled #5 - 112.5° Light Gray Part 32015 Element 4106378 ×2
  • Technic Axle and Pin Connector Perpendicular Light Gray Part 6536 Element 4173667 or 653602 ×2
  • Technic Axle and Pin Connector Perpendicular 3L with Pin Hole Light Gray Part 32068 Element 4114669 ×2
  • Technic Beam 1 x 3 Thin Light Gray Part 6632 Element 4107825 ×2
  • Technic Beam 1 x 5 Thin Light Gray Part 32017 Element 4106885 ×4
  • Technic Bush Light Gray Part 3713 Element 4125313 or 659002 1 spare in the box ×20
  • Technic Bush 1/2 Smooth with Axle Hole Reduced Light Gray Part 32123a 1 spare in the box ×4
  • Technic Gear 12 Tooth Bevel Light Gray Part 6589 Element 658902 ×9
  • Technic Gear 16 Tooth with Round Holes [Old Style] Light Gray Part 4019 Element 4107176 or 401902 ×4
  • Technic Gear 24 Tooth Crown with Reinforcements [New Style] Light Gray Part 3650c Element 365002 ×4
  • Technic Gear 24 Tooth [New Style with Single Axle Hole] Light Gray Part 3648b Element 4107543 or 364802 ×4
  • Technic Gear 8 Tooth Light Gray Part 3647 Element 364702 ×6
  • Technic Gear Rack 1 x 4 Light Gray Part 3743 Element 374302 ×4
  • Technic Pin 1/2 without Friction Ridges Light Gray Part 4274 Element 427402 1 spare in the box ×4
  • Technic Pin without Friction Ridges Lengthwise Light Gray Part 3673 Element 4184166 or 367302 ×12
  • Technic Wedge Belt Wheel [aka Pulley] Light Gray Part 4185 Element 4100502 or 418502 ×4

Yellow 96 pieces

  • Minifig Head Standard Grin Print [Blocked Open Stud] Yellow Part 3626bpr0001 Element 6020398 ×2
  • Minifig Head, Black Sunglasses and Standard Grin Print [Blocked Open Stud] Yellow Part 3626bpr0006 ×1
  • Minifig Head, Freckle Nose and Standard Grin Print [Blocked Open Stud] Yellow Part 3626bpr0009 ×1
  • Plate 1 x 10 Yellow Part 4477 Element 6079138 or 6078095 ×4
  • Plate 1 x 2 Yellow Part 3023 Element 302324 ×16
  • Plate 1 x 3 Yellow Part 3623 Element 362324 ×8
  • Plate 1 x 4 Yellow Part 3710 Element 371024 ×8
  • Plate 1 x 6 Yellow Part 3666 Element 366624 ×4
  • Plate 1 x 8 Yellow Part 3460 Element 346024 ×4
  • Plate 2 x 2 Yellow Part 3022 Element 4613978 or 302224 ×4
  • Plate 2 x 3 Yellow Part 3021 Element 302124 ×4
  • Plate 4 x 4 Yellow Part 3031 Element 4243817 or 303124 ×2
  • Plate 4 x 6 Yellow Part 3032 Element 303224 ×2
  • Plate 6 x 10 Yellow Part 3033 Element 303324 ×2
  • Technic Beam 1 x 11.5 Double Bent Thick Yellow Part 32009 Element 6271150 or 6257104 ×4
  • Technic Gearbox 2 x 4 x 3 1/3 Yellow Part 6588 Element 658824 ×1
  • Technic Pin Connector Round [No Slot] Yellow Part 75535 Element 75644 ×2
  • Technic Plate 2 x 4 [3 Holes] Yellow Part 3709 Element 370924 ×8
  • Technic Plate 2 x 6 [5 Holes] Yellow Part 32001 Element 6038194 or 4107750 ×2
  • Technic Plate 2 x 8 [7 Holes] Yellow Part 3738 Element 4624216 or 373824 ×4
  • Wheel Rim 24 x 14 VR with Center Axle Hole Yellow Part 2994 Element 4496673 or 299424 ×2
  • Wheel with Split Axle hole Yellow Part 3482 Element 348224 ×8
  • Wire with Brick 2 x 2 x 2/3 Pair, 26L Yellow Part 5306bc026 Element 4112988 ×3

White 14 pieces

  • Hips and White Legs White Part 970c27 Element 6551364 or 4570434 ×1
  • Light Brick 1 x 2 with Single Side Light White Part 6035 Element 4603220 or 74880 ×4
  • Technic Gear 24 Tooth Clutch with Dark Gray or Light Gray Center White Part 76019 Element 4270486 ×1
  • Tile 1 x 2 with Groove White Part 3069b Element 6548264 or 306901 ×6
  • Torso, Octan Logo Print, White Arms, Yellow Hands White Part 973c27h01pr0130 Element 6020973 or 74954 ×1
  • Torso, Palm Tree Print, White Arms, Yellow Hands White Part 973c27h01pr0017 ×1

Blue 13 pieces

  • Hat / Cap Long Peak [Plain] Blue Part 4485 Element 448523 ×1
  • Hips and Blue Legs Blue Part 970c28 Element 6006026 or 4583501 ×1
  • Hose Rigid 3mm D. 18L / 14.4cm Blue Part 75c18 Element 4517521 or 4116885 ×2
  • Hose Rigid 3mm D. 20L / 16cm Blue Part 75c20 Element 6006106 or 4116886 ×2
  • Sensor, Light with Fixed Cable Blue Part 2982c01 Element 4119421 ×2
  • Technic Axle and Pin Connector Angled #1 Blue Part 32013 Element 6332570 or 4107797 ×4
  • Torso, Jacket with Zipper and 3 Pockets Print, Blue Arms, Yellow Hands Blue Part 973c28h01pr1245 Element 4288269 ×1

Dark Gray 11 pieces

  • Technic Axle 3 with Stud Dark Gray Part 6587 Element 4113884 or 658727 ×2
  • Technic Gear Differential, 24 -16 Tooth with Clutch on Both Sides Dark Gray Part 6573 Element 657327 ×1
  • Technic Pin 3/4 Dark Gray Part 32002 Element 4109854 1 spare in the box ×8

Red 10 pieces

  • Hips and Red Legs Red Part 970c22 Element 6006024 or 4582576 ×1
  • Technic Rubber Belt Medium [24mm ID] [Round Cross Section] Red Part 85544 Element 4544145 or 4544143 ×2
  • Tile 1 x 2 with Groove Red Part 3069b Element 4178178 or 306921 ×6
  • Torso, Red Arms, Yellow Hands [Plain] Red Part 973c22h01 Element 4582740 or 4275872 ×1

Green 5 pieces

  • Baseplate 32 x 32 with 8-Stud Straight with Road Print Green Part 30279pr0001 Element 4220059 or 4109602 ×1
  • Technic Brick 1 x 2 with Axle Hole Type 2 [X Opening] Green Part 32064b ×4

[No Color/Any Color] 5 pieces

  • Activity Booklet 1 - Simple Traffic Lights - Set 9723 [No Color/Any Color] Part 9723b1 ×1
  • Activity Booklet 2 - Traffic Monitoring - Set 9723 [No Color/Any Color] Part 9723b2 ×1
  • Activity Booklet 3 - Intelligent Vehicles - Set 9723 [No Color/Any Color] Part 9723b3 ×1
  • Activity Booklet 4 - Monorail - Set 9723 [No Color/Any Color] Part 9723b4 ×1
  • Sticker Sheet for Storage Bin with Set 9723-1 [No Color/Any Color] Part 4230879 Element 4230879 ×1

Trans-Yellow 4 pieces

  • Brick 1 x 2 without Bottom Tube Trans-Yellow Part 3065 Element 6514265 or 6244907 ×4

Trans-Clear 2 pieces

  • Storage / Sorting Tray, Dacta, 29 Compartment for Dacta Small Bin Trans-Clear Part 4125890 ×1
  • Storage Bin Lid, Dacta, 19 x 24 Trans-Clear Part 71082 ×1

Trans-Green 2 pieces

  • Brick 1 x 2 without Bottom Tube Trans-Green Part 3065 Element 6514266 or 6244908 ×2

Trans-Red 2 pieces

  • Brick 1 x 2 without Bottom Tube Trans-Red Part 3065 Element 6514263 or 6244905 ×2

Brown 1 piece

  • Hair Center Parting Brown Part 4530 Element 453025 ×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.

Request a replacement from LEGO

Buy the piece

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.

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