How many pieces are in the Mobile Crane?

Mobile Crane contains 1,884 pieces.

When was the Mobile Crane released?

Mobile Crane was released in 2005.

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🏛 Technic

Set #8421

Mobile Crane

The Mobile Crane 8421-1 is a Technic masterpiece of engineering.

Before you buy

Who it's for: Advanced build Ideal for teens and adults with experience in Technic building and a passion for realistic vehicle models.
Build: 1,884 pieces · about 8 hours Build time is an estimate.
Price: $150.00 list price · 8.0¢ per piece
Availability: Retired at LEGO

★★★★☆ 4.4 community rating from 130 ratings

Highly regarded for its realistic functions and challenging build, the Mobile Crane 8421-1 is praised for its intricate pneumatic system and impressive size. Some builders find the instructions complex and the assembly time lengthy, but the finished model is generally considered a rewarding achievement.

$150.00

Best Price

$153.59

📝 Our Take

AI-assisted editorial summary, grounded in our LEGO database and public community discussions. How we use AI

The Mobile Crane 8421-1 is a Technic masterpiece of engineering. Released in 2005, this set boasts a fully functional telescoping boom, pneumatic cylinders, and six-wheel steering, showcasing the intricate mechanics that Technic sets are known for.

This set is perfect for experienced Technic builders and fans of realistic construction vehicles. The 1885-piece build provides a challenging and rewarding experience, resulting in a large and impressive model that's ideal for display.

Skip this if you're new to Technic or prefer simpler building experiences. The complex mechanisms and pneumatic functions may be daunting for beginners; consider a smaller Technic set like the 42162-1 Chevrolet Camaro Z28 for an easier introduction.

✨ New

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How does the Mobile Crane's pneumatic system compare to other Technic sets with similar functions? What are some common challenges builders face when assembling the Mobile Crane, and how can they be overcome? How does the value of the Mobile Crane compare to other retired Technic sets of similar size and complexity? What's the best way to display the Mobile Crane to showcase its features and functionality?

🧱 Building Experience

AI-assisted build estimate, grounded in our LEGO database and public community discussions. How we use AI

🧩

1,884

Pieces

⏱

Estimated Build Time

📊

Advanced

Difficulty

Build Highlights:

Intricate pneumatic system for raising and lowering the boom
Six-wheel steering mechanism for realistic maneuverability
Telescoping boom extends to twice its original length
Retractable outriggers provide stability during operation

📈 Investment Analysis

AI-assisted investment analysis, grounded in our LEGO database and public community discussions. How we use AI

→ Price stable

B+

Investment Grade

⏳ Retired

The Mobile Crane 8421-1 presents a solid investment opportunity due to its age, complexity, and status as a sought-after Technic set. As a retired set, its value has generally increased over time, and its high piece count and functional features contribute to its desirability among collectors. While the price trend is currently stable, demand could drive prices higher in the future, especially for sets in excellent condition with original packaging. However, potential investors should be aware of the risk of condition depreciation and the availability of alternative Technic crane models.

Not Financial Advice: Content is for educational purposes only. Past performance doesn't guarantee future results. Full disclaimer

📖 About This Set

The Mobile Crane towers above the construction site! This huge, detailed set features six-wheel steering, a telescoping boom that extends to twice its original length, pneumatic cylinders to raise and lower the boom, four retractable outriggers, motor and battery box. Authentic model for skilled builders!

• Includes motor and battery box to extend arm and lower hook!

• Measures over 18 inches/46 cm long!

• Pneumatic cylinder and air pump lift crane arm - release air pressure to lower boom.

• Arm extends over 25 inches/64 cm long!

• Boom rotates a full 360 degrees!

• Includes instructions to rebuild into an Aerial Lift!

• Realistic 6-wheel steering! Wheels drive pistons in V6 engine!

• Requires 6 AA (1.5v) batteries, not included.

6 Wheel Steering 8 Wheel Vehicle 9V Cherry Picker Construction Crane Electric Electric Motor Flagship Set Functional Steering Mobile Crane Multibuild Outriggers Pneumatic V6 Engine

⚖ Compare Similar Sets

Liebherr Crawler Crane LR 13000

Technic • 2,883 pcs

$699.99

The Mobile Crane 8421-1 is a classic Technic set known for its complexity and realistic functions. Compared to newer crane models like 42146-1 Liebherr Crawler Crane LR 13000, it offers a more traditional Technic building experience with pneumatic components. While the newer sets may have more advanced features and electronic controls, the 8421-1 provides a challenging and rewarding build for those who appreciate the intricacies of mechanical engineering in LEGO form.

📦 Parts Inventory

Official piece count: 1,884
Parts cataloged in this inventory: 141 unique parts, 1,885 pieces

LEGO counts 1,884 pieces. This inventory comes from a separate parts catalog and lists 1,885; the two do not always count the same elements, so their totals differ. Spare parts are counted in neither figure.

Missing a piece? Check this set piece by piece, with look-alike colors flagged and element IDs for replacements.

String with End S...

Part #: 14226c31 2× Black

String Cord Mediu...

Part #: 14728c250 1× Black

Plate 2 x 2 Corner

Part #: 2420 2× Yellow

Tile 1 x 4 with G...

Part #: 2431 1× Black

Tile 1 x 4 with G...

Part #: 2431 2× Yellow

Plate Special 2 x...

Part #: 2444 2× Black

Brick 2 x 6

Part #: 2456 4× Yellow

Plate Round 2 x 2...

Part #: 2654 3× Black

Technic Slope Lon...

Part #: 2744 6× Yellow

Technic Pin with ...

Part #: 2780 234× Black

Pneumatic Pump Ne...

Part #: 2797c02 1× Yellow

Plate Special 2 x...

Part #: 2817 1× Yellow

Technic Steering ...

Part #: 2819 1× Light Bluish Gray

Battery Box, 9V 4...

Part #: 2847c03 1× Yellow

Technic Engine Cy...

Part #: 2850a 6× Light Bluish Gray

Technic Engine Pi...

Part #: 2851 6× Yellow

Technic Engine Co...

Part #: 2852 6× Light Bluish Gray

Technic Engine Cr...

Part #: 2853 2× Light Bluish Gray

Technic Engine Cr...

Part #: 2854 2× Dark Bluish Gray

Technic Beam Tria...

Part #: 2905 14× Black

Wheel Spoked 2 x ...

Part #: 30155 2× Black

Plate 2 x 3

Part #: 3021 1× Yellow

Plate 2 x 2

Part #: 3022 3× Yellow

Plate 1 x 2

Part #: 3023 2× Dark Bluish Gray

Plate 1 x 2

Part #: 3023 13× Yellow

Plate 4 x 6

Part #: 3032 1× Dark Bluish Gray

Plate 2 x 8

Part #: 3034 1× Yellow

Plate 4 x 8

Part #: 3035 1× Dark Bluish Gray

Grille 1 x 4 [Two...

Part #: 30622 2× Yellow

Tile 1 x 2 with G...

Part #: 3069b 4× Yellow

Technic Pin 3/4

Part #: 32002 12× Dark Bluish Gray

Technic Beam 1 x ...

Part #: 32009 2× Black

Technic Beam 1 x ...

Part #: 32009 1× Yellow

Technic Beam 1 x ...

Part #: 32009 8× Dark Bluish Gray

Technic Axle and ...

Part #: 32013 12× Yellow

Technic Axle and ...

Part #: 32013 1× Black

Technic Axle and ...

Part #: 32013 8× Light Bluish Gray

Technic Axle and ...

Part #: 32015 2× Black

Technic Axle and ...

Part #: 32016 2× Black

Technic Beam 1 x ...

Part #: 32017 2× Light Bluish Gray

Technic Brick 1 x...

Part #: 32018 2× Black

Technic Brick 1 x...

Part #: 32018 5× Yellow

Tyre 62.4 x 20

Part #: 32019 8× Black

Wheel 43.2 x 18 w...

Part #: 32020 8× Light Bluish Gray

Technic Axle and ...

Part #: 32034 2× Light Bluish Gray

Technic Axle and ...

Part #: 32034 5× Black

Technic Axle Conn...

Part #: 32039 2× Black

Technic Axle Conn...

Part #: 32039 6× Yellow

Technic Pin Long ...

Part #: 32054 4× Black

Technic Pin Long ...

Part #: 32054 17× Light Bluish Gray

Technic Pin Long ...

Part #: 32054 29× Yellow

Technic Beam 3 x ...

Part #: 32056 14× Blue

Technic Axle 2 No...

Part #: 32062 24× Red

Technic Brick 1 x...

Part #: 32064b 2× Yellow

Technic Beam 1 x ...

Part #: 32065 1× Black

Technic Beam 1 x ...

Part #: 32065 1× Yellow

Technic Knob Wheel

Part #: 32072 4× Yellow

Technic Axle 5

Part #: 32073 40× Light Bluish Gray

Technic Bush 1/2 ...

Part #: 32123b 30× Light Bluish Gray

Technic Bush 1/2 ...

Part #: 32123b 4× Yellow

Technic Plate 1 x...

Part #: 32124 4× Black

Technic Pin Doubl...

Part #: 32138 3× Light Bluish Gray

Technic Pin Doubl...

Part #: 32138 1× Black

Technic Beam 2 x ...

Part #: 32140 32× Dark Bluish Gray

Technic Beam 2 x ...

Part #: 32140 2× Black

Technic Beam 2 x ...

Part #: 32140 6× Yellow

Technic Beam 2 x ...

Part #: 32140 3× Blue

Technic Axle and ...

Part #: 32184 28× Black

Technic Axle and ...

Part #: 32184 7× Light Bluish Gray

Technic Gear 20 T...

Part #: 32198 1× Light Bluish Gray

Technic Axle 5.5 ...

Part #: 32209 15× Dark Bluish Gray

Technic Beam 3 x ...

Part #: 32250 6× Black

Technic Beam 5 x ...

Part #: 32251 4× Black

Technic Gear 20 T...

Part #: 32269 5× Light Bluish Gray

Technic Gear 12 T...

Part #: 32270 5× Light Bluish Gray

Technic Beam 1 x ...

Part #: 32271 3× Yellow

Technic Beam 1 x ...

Part #: 32278 6× Black

Technic Beam 1 x ...

Part #: 32278 19× Light Bluish Gray

Technic Beam 1 x ...

Part #: 32278 8× Yellow

Technic Axle and ...

Part #: 32291 2× Black

Technic Beam 1 x ...

Part #: 32316 24× Light Bluish Gray

Technic Beam 1 x ...

Part #: 32316 18× Yellow

Technic Beam 1 x ...

Part #: 32316 1× Black

Technic Pin Conne...

Part #: 32333 2× Light Bluish Gray

Technic Beam 1 x ...

Part #: 32348 2× Light Bluish Gray

Technic Beam 1 x ...

Part #: 32449 4× Yellow

Technic Beam 1 x ...

Part #: 32449 17× Light Bluish Gray

Technic Gear 36 T...

Part #: 32498 1× Black

Technic Beam 1 x ...

Part #: 32523 7× Yellow

Technic Beam 1 x ...

Part #: 32523 2× Light Bluish Gray

Technic Beam 1 x ...

Part #: 32523 12× Dark Bluish Gray

Technic Beam 1 x ...

Part #: 32524 10× Yellow

Technic Beam 1 x ...

Part #: 32524 29× Light Bluish Gray

Technic Beam 1 x ...

Part #: 32525 3× Yellow

Technic Beam 1 x ...

Part #: 32525 6× Light Bluish Gray

Technic Beam 3 x ...

Part #: 32526 8× Black

Technic Beam 3 x ...

Part #: 32526 11× Light Bluish Gray

Technic Beam 3 x ...

Part #: 32526 6× Blue

Technic Beam 3 x ...

Part #: 32526 4× Yellow

Technic Pin Conne...

Part #: 32529 2× Black

Technic Pin Long ...

Part #: 32556a 13× Light Bluish Gray

Technic Beam 3 x ...

Part #: 33299a 4× Black

Plate 1 x 8

Part #: 3460 8× Dark Bluish Gray

Plate 1 x 8

Part #: 3460 6× Yellow

Plate 1 x 3

Part #: 3623 2× Dark Bluish Gray

Plate 1 x 3

Part #: 3623 6× Yellow

Technic Gear 8 Tooth

Part #: 3647 11× Light Bluish Gray

Technic Gear 24 T...

Part #: 3648b 1× Light Bluish Gray

Technic Gear 24 T...

Part #: 3650c 1× Light Bluish Gray

Brick Sloped Inve...

Part #: 3665 4× Dark Bluish Gray

Plate 1 x 6

Part #: 3666 10× Yellow

Plate 1 x 6

Part #: 3666 1× Light Bluish Gray

Plate 1 x 6

Part #: 3666 1× Black

Technic Brick 1 x...

Part #: 3701 4× Yellow

Technic Brick 1 x...

Part #: 3702 4× Yellow

Technic Brick 1 x...

Part #: 3703 16× Yellow

Technic Brick 1 x...

Part #: 3703 2× Dark Bluish Gray

Technic Axle 4

Part #: 3705 34× Black

Technic Axle 6

Part #: 3706 5× Black

Technic Axle 8

Part #: 3707 7× Black

Technic Axle 12

Part #: 3708 2× Black

Plate 1 x 4

Part #: 3710 16× Yellow

Technic Bush

Part #: 3713 17× Black

Technic Bush

Part #: 3713 52× Light Bluish Gray

Technic Axle 10

Part #: 3737 5× Black

Technic Gear Rack...

Part #: 3743 9× Light Bluish Gray

Technic Axle Pin ...

Part #: 3749 2× Tan

Plate Special 1 x...

Part #: 3794a 6× Light Bluish Gray

Plate Special 1 x...

Part #: 3794a 2× Yellow

Technic Brick 1 x...

Part #: 3894 4× Yellow

Brick Round 2 x 2...

Part #: 3941 3× Trans-Neon Orange

Technic Gear 16 T...

Part #: 4019 8× Light Bluish Gray

Plate Round 2 x 2...

Part #: 4032a 3× Black

Technic Beam 1 x ...

Part #: 40490 11× Dark Bluish Gray

Technic Beam 1 x ...

Part #: 40490 1× Light Bluish Gray

Technic Beam 1 x ...

Part #: 40490 2× Black

Technic Beam 1 x ...

Part #: 40490 4× Yellow

Technic Beam 1 x ...

Part #: 41239 14× Black

Technic Beam 1 x ...

Part #: 41239 2× Light Bluish Gray

Technic Beam 1 x ...

Part #: 41239 7× Yellow

Tile 1 x 8 with G...

Part #: 4162 14× Yellow

Large Figure Skel...

Part #: 41672 2× Black

Technic Beam 1 x ...

Part #: 41677 2× Black

Technic Beam 1 x ...

Part #: 41677 4× Light Bluish Gray

Technic Beam 1 x ...

Part #: 41677 12× Red

Technic Beam 1 x ...

Part #: 41677 6× Dark Bluish Gray

Technic Axle and ...

Part #: 41678 2× Yellow

Brick Wedged, Ang...

Part #: 41767 4× Yellow

Brick Wedged, Ang...

Part #: 41768 4× Yellow

Technic Wedge Bel...

Part #: 4185 2× Black

Technic Wedge Bel...

Part #: 4185 3× Light Bluish Gray

Technic Axle and ...

Part #: 42003 19× Light Bluish Gray

Technic Axle and ...

Part #: 42003 3× Yellow

Technic Pin 1/2 w...

Part #: 4274 20× Light Bluish Gray

Motor, RC Race Buggy

Part #: 42908 1× Black

Technic Axle Pin ...

Part #: 43093 106× Blue

Technic Beam 1 x ...

Part #: 43857 2× Yellow

Technic Beam 1 x ...

Part #: 43857 1× Light Bluish Gray

Technic Beam 1 x ...

Part #: 43857 2× Black

Technic Beam 1 x ...

Part #: 43857 2× Blue

Technic Axle 7

Part #: 44294 30× Light Bluish Gray

Plate 1 x 10

Part #: 4477 2× Black

Technic Axle 3

Part #: 4519 55× Light Bluish Gray

Pneumatic T-Piece...

Part #: 4697b 1× Light Bluish Gray

Technic Worm Gear

Part #: 4716 1× Light Bluish Gray

Technic Worm Gear

Part #: 4716 1× Black

Pneumatic Switch ...

Part #: 47223a 1× Dark Bluish Gray

Pneumatic Cylinde...

Part #: 47225 2× Yellow

Technic Pin Conne...

Part #: 48989 14× Light Bluish Gray

Technic Turntable...

Part #: 50163 1× Dark Bluish Gray

Technic Axle 32

Part #: 50450 1× Black

Hose, Pneumatic 4...

Part #: 5102c16 1× Blue

Hose, Pneumatic 4...

Part #: 5102c16 1× Black

Wire with Brick 2...

Part #: 5306bc020 1× Black

Pneumatic Cylinde...

Part #: 53178 2× Yellow

Sticker Sheet for...

Part #: 53535 1× [No Color/Any Color]

Plate Round 1 x 1...

Part #: 6141 2× Trans-Red

Plate Round 1 x 1...

Part #: 6141 6× Trans-Clear

Plate Round 1 x 1...

Part #: 6141 4× Trans-Neon Orange

Technic Axle and ...

Part #: 6536 18× Light Bluish Gray

Technic Axle and ...

Part #: 6536 17× Black

Technic Axle and ...

Part #: 6536 8× Dark Bluish Gray

Technic Axle and ...

Part #: 6536 34× Yellow

Technic Axle Conn...

Part #: 6538b 27× Light Bluish Gray

Technic Axle Conn...

Part #: 6538b 15× Black

Technic Driving R...

Part #: 6539 1× Red

Technic Brick 1 x...

Part #: 6541 2× Yellow

Technic Gear 16 T...

Part #: 6542a 5× Dark Bluish Gray

Technic Axle 1.5 ...

Part #: 6553 2× Black

Technic Pin Long ...

Part #: 6558 158× Black

Technic Gear Diff...

Part #: 6573 1× Dark Bluish Gray

Technic Axle 3 wi...

Part #: 6587 1× Dark Bluish Gray

Technic Gear 12 T...

Part #: 6589 5× Light Bluish Gray

Technic Beam 1 x ...

Part #: 6629 3× Black

Technic Beam 1 x ...

Part #: 6629 3× Yellow

Technic Beam 1 x ...

Part #: 6632 2× Yellow

Technic Beam 1 x ...

Part #: 6632 15× Light Bluish Gray

Technic Changeove...

Part #: 6641 1× Red

Hook, Technic - L...

Part #: 70496 1× Black

Technic Pin Conne...

Part #: 75535 2× Black

Technic Gear 24 T...

Part #: 76244 2× White

The Mobile Crane 8421-1 offers a substantial collection of Technic pins and axles, making it a valuable source for builders working on complex mechanical models. The abundance of black and light bluish gray elements provides a versatile palette for creating robust and functional structures.