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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.

Heavy-Duty Excavator

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42121 Heavy-Duty Excavator

569 pieces in 116 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

Technic Pins 169 pieces

  • Technic Axle Pin 3L with Friction Ridges Lengthwise and 2L Axle Black Part 18651 Element 6089119 ×12
  • Technic Pin with Friction Ridges Lengthwise with No Center Slots Black Part 61332 Element 6279875 2 spares in the box ×38
  • Technic Axle Pin with Friction Ridges Lengthwise Blue Part 43093 Element 4309323 or 4206482 ×14
  • Technic Pin Long with Friction Ridges Lengthwise, 1 Center Slot Blue Part 42924 Element 6299413 ×63
  • Technic Pin 1/2 without Friction Ridges Light Bluish Gray Part 4274 Element 4274194 or 4211483 2 spares in the box ×15
  • Technic Pin Long with Friction Ridges Lengthwise and Stop Bush [3 Lateral Holes, Big Pin Hole] Light Bluish Gray Part 32054 Element 4211865 ×6
  • Technic Axle Pin 3L with Friction Ridges Lengthwise and 1L Axle Red Part 11214 Element 6209519 ×7
  • Technic Pin Long with Friction Ridges Lengthwise and Stop Bush [2 Lateral Holes, Small Pin Hole] Red Part 65304 Element 6347789 ×4
  • Technic Axle Pin without Friction Ridges Lengthwise Tan Part 3749 Element 4666579 or 4186017 ×2
  • Technic Pin 3/4 Tan Part 32002 Element 6663097 or 6013938 1 spare in the box ×4
  • Technic Pin Long without Friction Ridges, with Anti-Roll Notch Tan Part 39888 Element 6321305 ×4

Technic Beams 114 pieces

  • Technic Beam 1 x 2 Thin Black Part 41677 Element 6338428 or 4167726 ×10
  • Technic Beam 1 x 3 Thick Black Part 32523 Element 4142822 or 3252326 ×2
  • Technic Beam 1 x 5 Thick Black Part 32316 Element 4142135 or 4140429 ×5
  • Technic Beam 1 x 5 Thin with Axle Holes on Ends Black Part 11478 Element 6327028 or 6030286 ×2
  • Technic Beam 1 x 9 Bent (7 - 3) Thick Black Part 32271 Element 6276835 or 4140327 ×4
  • Technic Beam 1 x 9 Thick Black Part 40490 Element 4645732 or 4542788 ×4
  • Technic Beam 2 x 3 L-Shape with Quarter Ellipse Thick Black Part 71708 Element 6326047 ×2
  • Technic Beam 2 x 4 L-Shape Thick Black Part 32140 Element 6271825 or 4120017 ×2
  • Technic Beam 3 x 5 L-Shape Thick Black Part 32526 Element 4142823 or 3252626 ×5
  • Technic Beam 3 x 5 L-Shape with Quarter Ellipse Thin Black Part 32250 Element 6327162 or 4128557 ×6
  • Technic Beam Triangle Thin [Type II] Black Part 99773 Element 6331437 or 6010864 ×4
  • Technic Connector Beam 3 x 3 Black Part 39793 Element 6265644 ×3
  • Technic Beam 1 x 11 Thick Dark Bluish Gray Part 32525 Element 4603472 or 4534914 ×5
  • Technic Beam 1 x 15 Thick Dark Bluish Gray Part 32278 Element 32278199 or 4542576 ×6
  • Technic Beam 1 x 2 Thick with Pin Hole and Axle Hole Dark Bluish Gray Part 60483 Element 6265093 or 6006141 ×20
  • Technic Beam 1 x 7 Thick Dark Bluish Gray Part 32524 Element 4495931 or 4210752 ×1
  • Technic Beam 1 x 9 Thick White Part 40490 Element 6001831 or 4156341 ×1
  • Technic Beam 1 x 11 Thick Yellow Part 32525 Element 6028107 or 4534912 ×2
  • Technic Beam 1 x 11.5 Double Bent Thick Yellow Part 32009 Element 6271150 or 6257104 ×2
  • Technic Beam 1 x 3 Thick Yellow Part 32523 Element 4153707 ×5
  • Technic Beam 1 x 3 Thin Yellow Part 6632 Element 6344174 or 4107823 ×2
  • Technic Beam 1 x 6 Thin Yellow Part 32063 Element 6170294 or 6063252 ×4
  • Technic Beam 1 x 7 Thick Yellow Part 32524 Element 4495934 or 4187082 ×4
  • Technic Beam 2 x 3 L-Shape with Quarter Ellipse Thick Yellow Part 71708 Element 6332412 ×4
  • Technic Beam 2 x 4 L-Shape Thick Yellow Part 32140 Element 6271828 or 4141628 ×6
  • Technic Beam 3 x 5 L-Shape Thick Yellow Part 32526 Element 4144022 ×3

Technic Special 89 pieces

  • Technic Link Tread with Beveled Edge Black Part 15379 Element 6047885 4 spares in the box ×86
  • Technic Digger Bucket 4 x 7 Dark Bluish Gray Part 24120 Element 6471569 or 6325981 ×1
  • Technic Linear Actuator Mini with Dark Bluish Gray Head and Orange Axle Light Bluish Gray Part 92693 Element 6221464 or 4612100 ×2

Technic Connectors 70 pieces

  • Technic Axle and Pin Connector Angled #1 Black Part 32013 Element 6284699 or 4107085 ×1
  • Technic Axle and Pin Connector Angled #2 - 180° Black Part 32034 Element 6271869 or 4107783 ×3
  • Technic Axle and Pin Connector Angled #6 - 90° Black Part 32014 Element 6268905 or 4107767 ×3
  • Technic Axle and Pin Connector Perpendicular Black Part 6536 Element 6261371 or 4173668 ×8
  • Technic Axle and Pin Connector Perpendicular 3L with Centre Pin Hole Black Part 32184 Element 6276951 or 4121667 ×1
  • Technic Axle and Pin Connector Perpendicular Triple Black Part 63869 Element 6362991 or 6007966 ×2
  • Technic Axle and Pin Connector Toggle Joint Smooth Black Part 32126 Element 6457112 or 6322045 ×2
  • Technic Pin Connector Round 1L [Beam] Black Part 18654 Element 6121485 1 spare in the box ×5
  • Technic Pin Connector Round [Slotted] Black Part 62462 Element 6173119 or 4526982 ×4
  • Technic Axle and Pin Connector Block 4 x 3 x 2 1/2 [Linear Actuator Holder] Dark Bluish Gray Part 61904 Element 6356106 or 4528038 ×1
  • Technic Pin Connector Hub with 1 Axle Dark Bluish Gray Part 22961 Element 6135014 ×7
  • Technic Pin Connector Hub with 2 Axles Dark Bluish Gray Part 27940 Element 6167281 ×1
  • Technic Axle and Pin Connector Perpendicular 3L with Centre Pin Hole Light Bluish Gray Part 32184 Element 6276969 or 4211621 ×5
  • Technic Axle and Pin Connector Perpendicular Double Split Light Bluish Gray Part 41678 Element 4211889 ×4
  • Technic Axle and Pin Connector Perpendicular Split Light Bluish Gray Part 92907 Element 6279023 or 4630114 ×1
  • Technic Axle and Pin Connector Perpendicular Triple Light Bluish Gray Part 63869 Element 6331441 or 4538007 ×4
  • Technic Driving Ring Connector Smooth [2 rounded and 2 flat side walls] Light Bluish Gray Part 42195 Element 6273212 ×3
  • Technic Pin Connector Hub Perpendicular 3L with 4 Pins (Squared Holes) Light Bluish Gray Part 65489 Element 6282158 ×1
  • Technic Pin Connector Hub with 2 Pins with Friction Ridges Lengthwise [Small Squared Pin Holes] Light Bluish Gray Part 44874 Element 6321303 ×5
  • Technic Pin Connector Round 1L [Beam] Light Bluish Gray Part 18654 Element 6183784 1 spare in the box ×1
  • Technic Axle Connector Smooth [with x Hole + Orientation] Yellow Part 59443 Element 4519010 ×1
  • Technic Pin Connector Hub with 1 Pin with Friction Ridges Lengthwise [Centered Friction Ridge] Yellow Part 65487 Element 6282151 ×5
  • Technic Pin Connector Perpendicular 2 x 2 Bent Yellow Part 44809 Element 6331919 or 4480924 ×2

Technic Axles 42 pieces

  • Technic Axle 4 Black Part 3705 Element 370526 ×6
  • Technic Axle 4 with Stop Dark Bluish Gray Part 87083 Element 6083620 or 4560177 ×2
  • Technic Axle 5.5 with Stop [Rounded Short End] Dark Bluish Gray Part 59426 Element 4508553 ×1
  • Technic Axle 3 Light Bluish Gray Part 4519 Element 4211815 ×13
  • Technic Axle 5 Light Bluish Gray Part 32073 Element 32073194 or 4211639 ×1
  • Technic Axle 9 Light Bluish Gray Part 60485 Element 4535768 ×1
  • Technic Axle 2 Notched Red Part 32062 Element 4142865 ×6
  • Technic Axle 6 Red Part 3706 Element 6130002 or 4191526 ×1
  • Technic Axle 3 with Stop Reddish Brown Part 24316 Element 6135494 ×10
  • Technic Axle 7 Yellow Part 44294 Element 6130009 ×1

Technic Gears 18 pieces

  • Technic Gear 12 Tooth Double Bevel Black Part 32270 Element 4177431 ×3
  • Technic Turntable Large Type 3 Top, 60 Tooth Black Part 18938 Element 6109283 ×1
  • Technic Gear 8 Tooth [Reinforced] Dark Bluish Gray Part 10928 Element 6631413 or 6012451 ×6
  • Technic Gear 16 Tooth Reinforced [New Style] Light Bluish Gray Part 94925 Element 4640536 ×4
  • Technic Turntable Large Type 3 Base Light Bluish Gray Part 18939 Element 6109285 ×1
  • Technic Gear 12 Tooth Bevel Tan Part 6589 Element 4565452 or 4514556 ×1
  • Technic Gear 20 Tooth Bevel Tan Part 32198 Element 6031962 or 4514557 ×1
  • Technic Gear 20 Tooth Double Bevel with Axle Hole Type 1 [+ Opening] Tan Part 18575 Element 6346517 or 6084724 ×1

Plates Special 7 pieces

  • Plate Special 1 x 2 with 1 Stud with Groove and Inside Stud Holder (Jumper) Black Part 15573 Element 6092585 ×1
  • Plate Special 1 x 2 with Pin Hole Underneath Black Part 18677 Element 6192309 or 6167497 ×2
  • Plate Special 2 x 2 with Groove and Center Stud (Jumper) Red Part 87580 Element 6126048 or 4581308 ×4

Technic Panels 7 pieces

  • Technic Panel Curved and Bent 6 x 3 Trans-Clear Part 24116 Element 6329052 or 6268014 ×1
  • Technic Panel Curved and Bent 6 x 3 Yellow Part 24116 Element 6268010 or 6133245 ×3
  • Technic Panel Fairing # 3 Small Smooth Long, Side A Yellow Part 64683 Element 6533795 or 6005195 ×1
  • Technic Panel Fairing # 4 Small Smooth Long, Side B Yellow Part 64391 Element 6533801 or 6005197 ×1
  • Technic Panel Fairing #22 5L Small Smooth, Side A Yellow Part 11947 Element 6352686 or 6251191 ×1

Technic Bushes 6 pieces

  • Technic Bush Light Bluish Gray Part 3713 Element 6275844 or 6271817 1 spare in the box ×1
  • Technic Bush 1/2 Smooth with Axle Hole Semi-Reduced Yellow Part 32123b Element 6271167 or 3212324 1 spare in the box ×5

Bricks Curved 5 pieces

  • Brick Curved 2 x 1 No Studs [1/2 Bow] Red Part 11477 Element 6029946 ×1
  • Brick Curved 2 x 2 x 2/3 Yellow Part 15068 Element 6079007 ×4

Bricks Sloped 5 pieces

  • Brick Sloped 18° 2 x 1 x 2/3 with 4 Slots / Grate Black Part 61409 Element 4541191 ×4
  • Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope) Black Part 54200 Element 4504382 or 4287159 1 spare in the box ×1

Plates 5 pieces

  • Plate 2 x 2 Black Part 3022 Element 302226 ×1
  • Plate 1 x 3 Red Part 3623 Element 362321 ×1
  • Plate 1 x 2 Yellow Part 3023 Element 302324 ×1
  • Plate 1 x 4 Yellow Part 3710 Element 371024 ×1
  • Plate 4 x 6 Yellow Part 3032 Element 303224 ×1

Tiles 5 pieces

  • Tile 1 x 2 with Groove Light Bluish Gray Part 3069b Element 4211414 ×2
  • Tile 1 x 1 with Groove Red Part 3070b Element 307021 1 spare in the box ×2
  • Tile 2 x 4 with Groove Yellow Part 87079 Element 6388490 or 4560181 ×1

Bricks Round and Cones 4 pieces

  • Cone 1 x 1 [Top Groove] Red Part 59900 Element 4529234 ×4

Plates Round Curved and Dishes 4 pieces

  • Plate Round 1 x 1 with Solid Stud White Part 6141 Element 6601919 or 614101 1 spare in the box ×4

Technic Steering, Suspension and Engine 4 pieces

  • Technic Universal Joint 3L [Complete Assembly] Light Bluish Gray Part 61903 Element 6335279 or 6321309 ×4

Tiles Special 4 pieces

  • Tile Special 1 x 2 Grille with Bottom Groove Black Part 2412b Element 241226 ×4

Tiles Round and Curved 3 pieces

  • Tile Round 1 x 1 Light Bluish Gray Part 98138 Element 6284071 or 4650260 1 spare in the box ×1
  • Tile Round 1 x 1 Trans-Clear Part 98138 Element 6514191 or 6274738 1 spare in the box ×2

Hinges, Arms and Turntables 2 pieces

  • Hinge Cylinder 1 x 2 Locking with 2 Click Fingers and Axle Hole, 7 Teeth Black Part 57360 Element 6271535 ×1
  • Hinge Plate 1 x 2 Locking with 1 Finger on Side, without Groove Black Part 44567b Element 6266244 ×1

Minifig Accessories 2 pieces

  • Equipment Hose Nozzle / Gun with Side String Hole Simplified Light Bluish Gray Part 60849 Element 6641461 or 4515897 1 spare in the box ×2

Bars, Ladders and Fences 1 piece

  • Light Cover 1 x 1 Round with Internal Bar / Bionicle Barraki Eye Trans-Orange Part 58176 Element 6507868 or 6171764 1 spare in the box ×1

Bricks Special 1 piece

  • Brick Special 1 x 1 with Studs on 2 Sides Red Part 47905 Element 6030266 or 4550236 ×1

Stickers 1 piece

  • Sticker Sheet for Set 42121-1 [No Color/Any Color] Part 72184 Element 6323407 ×1

Technic Bricks 1 piece

  • Technic Brick 1 x 2 [2 Pin Holes] Black Part 32000 Element 3200026 ×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.

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