BlockTalk Find Your Set

Free tool

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.

Diesel Freight Train Set, battery

Checking

7720 Diesel Freight Train Set, battery

416 pieces in 101 part and color combinations, plus 3 minifigures.

LEGO counts 425 pieces. This inventory comes from a separate parts catalog and lists 428, including the 12 parts inside the minifigures; 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.

Show

Piece checklist

Black 124 pieces

  • Bar 1 x 4 x 2 with Studs Black Part 4083 Element 408326 ×1
  • Brick 1 x 2 Black Part 3004 Element 300426 ×2
  • Brick 1 x 4 Black Part 3010 Element 301026 ×1
  • Brick 1 x 6 Black Part 3009 Element 300926 ×8
  • Brick 2 x 4 Black Part 3001 Element 300126 ×1
  • Brick Sloped Inverted 45° 2 x 1 Black Part 3665 Element 366526 ×16
  • Brick Special 1 x 1 with Headlight Black Part 4070 Element 407026 ×2
  • Construction Vehicle Bucket Arm, Small - 2 x 6 x 2 Black Part 3314 Element 331426 ×1
  • Hinge Plate 2 x 5 with Large Hole [Complete Assembly] Black Part 3149bc01 Element 4161112 or 4106943 ×1
  • Magnet Cylindrical Black Part 73092 Element 73092 ×6
  • Motor, Train, 4.5V 12 x 4 x 3 1/3 Type II Black Part upn0259c01 ×1
  • Plate 1 x 1 Black Part 3024 Element 302426 ×8
  • Plate 1 x 2 Black Part 3023 Element 302326 ×2
  • Plate 1 x 3 Black Part 3623 Element 362326 ×4
  • Plate 1 x 4 Black Part 3710 Element 371026 ×4
  • Plate 1 x 6 Black Part 3666 Element 366626 ×15
  • Plate 1 x 8 Black Part 3460 Element 346026 ×2
  • Plate 2 x 10 Black Part 3832 Element 383226 ×2
  • Plate 2 x 2 Black Part 3022 Element 302226 ×6
  • Plate 2 x 3 Black Part 3021 Element 302126 ×2
  • Plate 2 x 6 Black Part 3795 Element 379526 ×4
  • Plate 4 x 8 Black Part 3035 Element 303526 ×1
  • Plate 6 x 10 Black Part 3033 Element 303326 ×1
  • Plate 6 x 16 Black Part 3027 Element 302726 ×1
  • Plate 6 x 8 Black Part 3036 Element 303676 or 303626 ×1
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thin Ring] Black Part 4081a ×2
  • Plate Special 1 x 2 with 1 Stud without Groove (Jumper) Black Part 3794a ×8
  • Plate Special 2 x 2 with Wheels Red Black Part 122c01 ×2
  • Train Buffer Beam Black Part 4022 Element 4109853 or 402276 ×4
  • Train Buffer Single Black Part 3488 ×4
  • Train Coupling Black Part 4023 ×6
  • Tyre 21 x 8 Offset Tread Medium Black Part 4084 ×4
  • Vehicle Base, Train 6 x 16 Black Part 4178 ×1

Red 92 pieces

  • Brick 1 x 1 Red Part 3005 Element 300521 ×14
  • Brick 1 x 2 Red Part 3004 Element 4613961 or 300421 ×8
  • Brick 1 x 4 Red Part 3010 Element 301021 ×7
  • Brick 2 x 2 without Inside Ridges Red Part 3003a ×2
  • Brick Sloped 45° 2 x 2 Red Part 3039 Element 303921 ×2
  • Brick Special 1 x 1 with Headlight Red Part 4070 Element 407021 ×8
  • Brick Special 1 x 1 x 2 with Shutter Holder Red Part 3581 Element 4207299 or 358121 ×4
  • Brick Special 1 x 2 with Cable Holding Square Cutout Red Part 3134 Element 4164407 or 313421 ×1
  • Door 1 x 4 x 5 Train Left Red Part 4181 Element 4502192 or 4100372 ×2
  • Door 1 x 4 x 5 Train Right Red Part 4182 Element 6219679 or 4297084 ×2
  • Plate 1 x 1 Red Part 3024 Element 302421 ×4
  • Plate 1 x 3 Red Part 3623 Element 362321 ×4
  • Plate 1 x 4 Red Part 3710 Element 371021 ×4
  • Plate 2 x 6 Red Part 3795 Element 379521 ×5
  • Plate 4 x 6 Red Part 3032 Element 303221 ×4
  • Train Direction Switch - 4.5V 2 x 3 Red Part 3218 ×1
  • Train Signal Circuit-Breaker Bar Red Part upn0387 ×1
  • Train Signal Post Red Part upn0262 ×1
  • Train Wheel Spoked for Motor Red Part upn0383a ×4
  • Wheels Train Spoked Small (23mm D.) and Black Brick, Modified 2 x 4 [Red] Red Part 4180c04 ×4
  • Window 1 x 2 x 2 Classic, Short Lip [with Glass] Red Part 3081c01 Element 7026 ×4
  • Window 1 x 2 x 2 Shutter Red Part 3582 Element 358221 ×4
  • Window 1 x 2 x 3 Train Red Part 4035 Element 4114302 ×1
  • Window 1 x 4 x 3 Train with All Studs Hollow Red Part 4033 Element 4100371 ×1

Light Gray 84 pieces

  • Battery Cover, Train Car Roof 6 x 14 Light Gray Part 699 ×1
  • Brick Sloped 33° 3 x 2 Light Gray Part 3298 Element 329802 ×2
  • Brick Sloped 33° 3 x 4 Light Gray Part 3297 Element 329702 ×11
  • Brick Sloped 45° 2 x 2 Light Gray Part 3039 Element 303902 ×2
  • Brick Sloped 45° 2 x 4 Light Gray Part 3037 Element 303702 ×2
  • Fence Lattice 1 x 4 x 1 Light Gray Part 3633 Element 4207300 or 363302 ×8
  • Plate 1 x 4 Light Gray Part 3710 Element 371002 ×2
  • Plate 1 x 6 Light Gray Part 3666 Element 366602 ×2
  • Plate 1 x 8 Light Gray Part 3460 Element 346002 ×2
  • Plate 4 x 6 Light Gray Part 3032 Element 303202 ×1
  • Plate 6 x 12 Light Gray Part 3028 Element 302802 ×2
  • Plate Special 1 x 2 with Ladder Light Gray Part 4175 Element 4100526 or 417502 ×2
  • Tyre for Train Wheel for Electric Train Motor 12V Light Gray Part 458 ×4
  • Vehicle Track, Train, Level Crossing Base Light Gray Part 813 ×1
  • Vehicle Track, Train, Level Crossing Center Rail Cap Insert 2 x 14 x 2/3 Light Gray Part 812 ×1
  • Vehicle Track, Train, Slotted Rail Curved Inside Light Gray Part 3230b ×16
  • Vehicle Track, Train, Slotted Rail Curved Outside Light Gray Part 3229b ×16
  • Vehicle Track, Train, Slotted Rail Straight Light Gray Part 3228b Element 322802 ×8
  • Wire with 2-Prong Connectors, 12V / 4.5V 28L Light Gray Part upn0123c28 ×1

Yellow 50 pieces

  • Brick 1 x 1 Yellow Part 3005 Element 300524 ×8
  • Brick 1 x 2 Yellow Part 3004 Element 4613966 or 300424 ×11
  • Brick 1 x 4 Yellow Part 3010 Element 301024 ×2
  • Brick 1 x 6 Yellow Part 3009 Element 300924 ×1
  • Brick Special 1 x 2 with Digger Bucket Arm Holder Yellow Part 3317 Element 331724 ×1
  • Construction Vehicle Bucket Smooth 3 x 5 x 1 & 1/3 Yellow Part 3433 Element 343324 ×1
  • Plate 1 x 2 Yellow Part 3023 Element 302324 ×4
  • Plate 1 x 4 Yellow Part 3710 Element 371024 ×5
  • Plate 2 x 3 Yellow Part 3021 Element 302124 ×2
  • Plate 2 x 4 Yellow Part 3020 Element 302024 ×1
  • Plate 2 x 6 Yellow Part 3795 Element 379524 ×1
  • Steering Stand 1 x 2 with Black Steering Wheel Yellow Part 3829c01 Element 9553 ×1
  • Window 1 x 2 x 3 Shutter Yellow Part 3856 Element 4141366 or 4108107 ×8
  • Window 1 x 4 x 3 Yellow Part 3853 Element 4189096 or 385324 ×4

Dark Gray 40 pieces

  • Train Track Sleeper Plate 2 x 8 without Cable Grooves Dark Gray Part 767 ×40

Trans-Clear 6 pieces

  • Glass for Train Door Lip On Top and Bottom Trans-Clear Part 4183 Element 418340 ×4
  • Glass for Train Window 1 x 2 x 3 Trans-Clear Part 4036 Element 403640 ×1
  • Glass for Train Window 1 x 4 x 3 Trans-Clear Part 4034 Element 403440 ×1

Trans-Red 6 pieces

  • Plate Round 1 x 1 with Solid Stud Trans-Red Part 6141 Element 6514051 or 6208450 ×6

Trans-Yellow 6 pieces

  • Plate Round 1 x 1 with Solid Stud Trans-Yellow Part 6141 Element 6514056 or 6240216 ×6

Blue 5 pieces

  • Battery Box, Train Car with Black Base, Red Wheels and Magnets Blue Part 3443c02 ×1
  • Brick 1 x 2 Blue Part 3004 Element 4613959 or 300423 ×4

White 2 pieces

  • Train Level Crossing Gate Type 1, Assembly with Blue Base & Red Handle (Left) White Part 815c02 ×1
  • Train Level Crossing Gate Type 1, Assembly with Blue Base & Red Handle (Right) White Part 815c01 ×1

[No Color/Any Color] 1 piece

  • Sticker Sheet for Set 7720-1 [No Color/Any Color] Part 191895 ×1

Minifigures 3 figures

  • Man, Blue Shirt, Blue Legs, Red Hard Hat Minifigure, checked as a whole figure ×1
  • Man - Blue Jacket, Blue Legs, Red Hat Minifigure, checked as a whole figure ×1
  • Man - Blue Jacket, Blue Legs, Red Hat Minifigure, checked as a whole figure ×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.

We value your privacy

We use cookies 🍪 for analytics and to improve your experience. Read our privacy policy