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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.

Mindstorms NXT

Checking

8527 Mindstorms NXT

579 pieces in 89 part and color combinations.

LEGO counts 577 pieces. This inventory comes from a separate parts catalog and lists 579; the two do not always count the same elements, so their totals differ. Spare parts are counted in neither figure.

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 248 pieces

  • Cable, Connector, 20cm for NXT Black Part 55804 Element 6089561 or 4297187 ×1
  • Cable, Connector, 35cm for NXT Black Part 55805 Element 6178439 or 6089560 ×4
  • Cable, Connector, 50cm for NXT Black Part 55806 Element 6178448 or 6089559 ×2
  • Cable, USB, 2m for NXT Black Part 57482 Element 4532371 ×1
  • Technic Axle 10 Black Part 3737 Element 373726 ×4
  • Technic Axle 12 Black Part 3708 Element 370826 ×2
  • Technic Axle 2 Notched Black Part 32062 Element 4109810 or 3206226 ×22
  • Technic Axle 4 Black Part 3705 Element 370526 ×4
  • Technic Axle 6 Black Part 3706 Element 370626 ×4
  • Technic Axle 8 Black Part 3707 Element 370726 ×2
  • Technic Axle Connector Double Flexible [Rubber] Black Part 45590 Element 4198367 ×8
  • Technic Axle Connector with Axle Hole Black Part 32039 Element 4107081 or 3203926 ×4
  • Technic Axle and Pin Connector Angled #1 Black Part 32013 Element 6284699 or 4107085 ×4
  • Technic Axle and Pin Connector Angled #2 - 180° Black Part 32034 Element 6271869 or 4107783 ×2
  • Technic Axle and Pin Connector Angled #4 - 135° Black Part 32192 Element 6262897 or 4121610 ×2
  • Technic Axle and Pin Connector Angled #6 - 90° Black Part 32014 Element 6268905 or 4107767 ×16
  • Technic Axle and Pin Connector Perpendicular 3L with Centre Pin Hole Black Part 32184 Element 6276951 or 4121667 ×4
  • Technic Beam Triangle Thin [Type I] Black Part 2905 Element 4142543 or 290526 ×4
  • Technic Gear 12 Tooth Double Bevel Black Part 32270 Element 4177431 ×4
  • Technic Gear 36 Tooth Double Bevel Black Part 32498 Element 4255563 or 4177434 ×1
  • Technic Knob Wheel Black Part 32072 Element 6284188 or 4248204 ×4
  • Technic Link 1 x 9 Black Part 32293 Element 6244698 or 4141300 ×2
  • Technic Pin Connector Perpendicular Long Black Part 32557 Element 4143466 ×4
  • Technic Pin Connector Round [Slotted] Black Part 62462 Element 6173119 or 4526982 ×4
  • Technic Pin Double with Axle Hole Black Part 32138 Element 4130597 or 4119589 ×3
  • Technic Pin Long with Friction Ridges Lengthwise and Stop Bush [3 Lateral Holes, Big Pin Hole] Black Part 32054 Element 4140801 or 4107742 ×8
  • Technic Pin Long with Friction Ridges Lengthwise, 2 Center Slots Black Part 6558 Element 655826 ×34
  • Technic Pin with Friction Ridges Lengthwise and Center Slots Black Part 2780 Element 4121715 or 278026 2 spares in the box ×80
  • Technic Pin with Friction Ridges Lengthwise and Towball Black Part 6628 Element 4184169 or 662826 ×8
  • Technic Worm Gear Black Part 4716 Element 6037533 or 471626 ×2
  • Tyre 56 x 26 Balloon Black Part 55976 Element 6495636 or 4297209 ×4

Light Bluish Gray 123 pieces

  • Technic Axle 1.5 with Perpendicular Axle Connector (Technic Pole Reverser Handle) Light Bluish Gray Part 6553 Element 4211536 ×1
  • Technic Axle 3 Light Bluish Gray Part 4519 Element 4211815 ×17
  • Technic Axle 5 Light Bluish Gray Part 32073 Element 32073194 or 4211639 ×7
  • Technic Axle 7 Light Bluish Gray Part 44294 Element 44294194 or 4211805 ×4
  • Technic Axle Towball Light Bluish Gray Part 2736 Element 6443149 or 4211375 ×2
  • Technic Axle and Pin Connector Perpendicular Light Bluish Gray Part 6536 Element 6261375 or 4211775 ×8
  • Technic Bush Light Bluish Gray Part 3713 Element 6275844 or 6271817 1 spare in the box ×16
  • Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced Light Bluish Gray Part 32123b Element 6271165 or 4211573 3 spares in the box ×6
  • Technic Gear 16 Tooth with Round Holes [Old Style] Light Bluish Gray Part 4019 Element 4562487 or 4211563 ×2
  • Technic Gear 20 Tooth Double Bevel with Axle Hole Type 2 [X Opening] Light Bluish Gray Part 32269 Element 32269194 or 4211635 ×2
  • Technic Gear 24 Tooth [New Style with Single Axle Hole] Light Bluish Gray Part 3648b Element 4211565 ×7
  • Technic Gear 40 Tooth Light Bluish Gray Part 3649 Element 6195314 or 4285634 ×1
  • Technic Gear 8 Tooth Light Bluish Gray Part 3647 Element 4211432 or 3647194 1 spare in the box ×6
  • Technic Pin Connector Hub Perpendicular 3 x 3 Bent with 4 Pins (Pin Ridges Across Part) Light Bluish Gray Part 55615 Element 4296059 ×8
  • Technic Pin Connector Hub Perpendicular 3L with 4 Pins Light Bluish Gray Part 48989 Element 4225033 ×13
  • Technic Pin Connector Perpendicular 2 x 2 Bent Light Bluish Gray Part 44809 Element 4211880 ×1
  • Technic Pin Long without Friction Ridges - Single Slot Light Bluish Gray Part 32556a Element 4211709 ×13
  • Technic Pin without Friction Ridges Lengthwise Light Bluish Gray Part 3673 Element 4211807 or 3673194 ×3
  • Technic Wedge Belt Wheel [aka Pulley] Light Bluish Gray Part 4185 Element 6321743 or 4494222 ×2
  • Wheel 30.4 x 20 without Pinholes, with Reinforced Rim Light Bluish Gray Part 56145 Element 4297210 ×4

Dark Bluish Gray 99 pieces

  • Technic Axle 3 with Stud Dark Bluish Gray Part 6587 Element 6587199 or 6129590 ×4
  • Technic Axle 5.5 with Stop [Rounded Short End] Dark Bluish Gray Part 59426 Element 4508553 ×2
  • Technic Axle Connector Ridged [with x Hole x Orientation] Dark Bluish Gray Part 6538b Element 6538199 or 4210672 ×2
  • Technic Axle and Pin Connector Perpendicular 3L with 2 Pin Holes Dark Bluish Gray Part 42003 Element 6273715 or 4210857 ×6
  • Technic Axle and Pin Connector Perpendicular Double Dark Bluish Gray Part 32291 Element 6280395 or 4210655 ×6
  • Technic Axle and Pin Connector Perpendicular Double Split Dark Bluish Gray Part 41678 Element 4234599 ×6
  • Technic Beam 1 x 11.5 Double Bent Thick Dark Bluish Gray Part 32009 Element 6271155 or 4210668 ×6
  • Technic Beam 1 x 3 Thick Dark Bluish Gray Part 32523 Element 32523199 or 4210751 ×16
  • Technic Beam 1 x 5 Thick Dark Bluish Gray Part 32316 Element 32316199 or 4210686 ×5
  • Technic Beam 1 x 7 Bent (4 - 4) Thick Dark Bluish Gray Part 32348 Element 32348199 or 6278127 ×16
  • Technic Beam 1 x 9 Bent (7 - 3) Thick Dark Bluish Gray Part 32271 Element 6276837 or 4281516 ×2
  • Technic Beam 2 x 4 L-Shape Thick Dark Bluish Gray Part 32140 Element 6271830 or 4210667 ×10
  • Technic Beam 3 x 5 L-Shape Thick Dark Bluish Gray Part 32526 Element 4210753 ×8
  • Technic Brick 1 x 4 [3 Pin Holes] Dark Bluish Gray Part 3701 Element 4213607 or 370127 ×4
  • Technic Brick 1 x 6 [5 Pin Holes] Dark Bluish Gray Part 3894 Element 4210917 or 3894199 ×2
  • Technic Link 1 x 6 with Stoppers Dark Bluish Gray Part 32005b ×3
  • Technic Turntable Large Type 2, 24/56 Tooth with Black Outside Gear Section [Complete Assembly] Dark Bluish Gray Part 50163 Element 4520872 or 4235858 ×1

Blue 43 pieces

  • Ball, Hard Plastic, 51mm (approx. 6 studs diameter) Blue Part 41250 Element 4100758 ×1
  • Technic Axle Pin with Friction Ridges Lengthwise Blue Part 43093 Element 4309323 or 4206482 ×42

Very Light Bluish Gray 43 pieces

  • Hub, NXT Brick with Dark Bluish Gray Base [Complete Assembly] Very Light Bluish Gray Part 53788 Element 6034375 or 6006064 ×1
  • Motor, NXT Very Light Bluish Gray Part 53787 Element 6122000 or 4297008 ×3
  • Sensor, Light, NXT Very Light Bluish Gray Part 55969 Element 6036227 or 4296917 ×1
  • Sensor, Sound, NXT Very Light Bluish Gray Part 55963 Element 6115463 or 4629679 ×1
  • Sensor, Touch, NXT Very Light Bluish Gray Part 53793 Element 4296929 ×1
  • Sensor, Ultrasonic, NXT Very Light Bluish Gray Part 53792 Element 6115469 or 4297174 ×1
  • Technic Beam 1 x 11 Thick Very Light Bluish Gray Part 32525 Element 4534916 or 4297200 ×7
  • Technic Beam 1 x 13 Thick Very Light Bluish Gray Part 41239 Element 4522939 or 4297203 ×4
  • Technic Beam 1 x 15 Thick Very Light Bluish Gray Part 32278 Element 4548305 or 4297197 ×11
  • Technic Beam 1 x 7 Thick Very Light Bluish Gray Part 32524 Element 4495932 or 4297199 ×6
  • Technic Beam 1 x 9 Thick Very Light Bluish Gray Part 40490 Element 4297202 ×7

Orange 8 pieces

  • Technic Tooth 1 x 3 with Axle Hole [Rounded Underside] Orange Part 41669 Element 4281515 or 4175219 ×8

Pearl Light Gray 4 pieces

  • Large Figure Weapon, Claw / Fang, 2 Pin Holes (Visorak Suukorak) Pearl Light Gray Part 50914 Element 4297208 or 4252701 ×4

Tan 4 pieces

  • Technic Axle Pin without Friction Ridges Lengthwise Tan Part 3749 Element 4666579 or 4186017 1 spare in the box ×4

White 3 pieces

  • Cone 1 x 1 [No Top Groove] White Part 4589 Element 458901 ×3

[No Color/Any Color] 3 pieces

  • CD-Rom, for 8527 Mindstorms NXT v1.0 [No Color/Any Color] Part 4493852 ×1
  • Playmat, Test Mat for Mindstorms NXT [No Color/Any Color] Part 40682 Element 4297446 ×1
  • Sticker Sheet for Set 8527-1 [No Color/Any Color] Part 57103 Element 4299391 ×1

Red 1 piece

  • Ball, Hard Plastic, 51mm (approx. 6 studs diameter) Red Part 41250 Element 4156530 ×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.