John Deere 8420 Specs & Review

Technical Specifications of John Deere 8420 Farm Tractor


  • Manufacturer: John Deere
  • Type: Row-Crop tractor
  • Factory: Waterloo, Iowa, USA
  • Series: 8020 Series
  • Variants: 8420 (wheeled tractor), 8420T (crawler)

Engine Specifications

  • Engine (gross): 284 hp (211.8 kW)
  • Engine (net): 270 hp (201.3 kW)
  • Engine (max): 314 hp (234.1 kW)
  • PTO (claimed): 235 hp (175.2 kW)
  • Drawbar (tested): 207.49 hp (154.7 kW)
  • PTO (tested): 269.41 hp (200.9 kW)
  • Engine Type: John Deere 8.1L 6-cyl diesel

Mechanical Specifications

  • Chassis: 4×4 MFWD 4WD
  • Steering: Hydrostatic power
  • Brakes: Hydraulic wet disc
  • Trailer brakes: Hydraulic
  • Cab: Standard
  • Transmission: 16-speed full power shift


  • Fuel: 160 gal (605.6 L)
  • Hydraulic system: 37 gal (140.0 L)
  • ILS Hydraulic system: 39.6 gal (149.9 L)
  • Front hubs: 3.6 qts (3.4 L)
  • ILS Front hubs: 4.2 qts (4.0 L)
  • Front diff.: 14.2 qts (13.4 L)


  • Type: Closed center pressure-flow compensated (PFC)
  • Capacity: 37 gal (140.0 L)
  • ILS Capacity: 39.6 gal (149.9 L)
  • Pressure: 2900 psi (200.0 bar)
  • Valves: 4 to 5
  • SCV flow: 30 gpm (113.6 lpm)
  • Total flow: 33.5 gpm (126.8 lpm)

Tractor Hitch

  • Rear Type: III/IIIN
  • Rear lift: 15180 lbs (6885 kg)
  • Front Hitch: IIIN
  • Front lift: 11000 lbs (4989 kg)

Power Take-off (PTO)

  • Rear PTO: Independent
  • Clutch: Hydraulic wet discs
  • Rear RPM: 1000 (1.75), 540/1000 (1.375 optional)
  • Engine RPM: 540@1975, 1000@2200

Dimensions & Tires

  • Wheelbase: 118.9 inches (302 cm)
  • Weight: 21650 to 23780 pounds
  • Front tire: 16.9R30
  • Rear tire: 18.4R46

Frequently Asked Questions

What is the engine power of the John Deere 8420?

The gross engine power is 284 hp, and the net engine power is 270 hp.

What type of transmission does it have?

It has a 16-speed full power shift transmission.

What is the fuel capacity?

The fuel capacity is 160 gallons.

How many hydraulic valves does it have?

It has 4 to 5 hydraulic valves.

What is the rear lift capacity?

The rear lift capacity is 15180 lbs.

What type of steering does it have?

It has hydrostatic power steering.

What are the front and rear tire sizes?

The front tire size is 16.9R30 and the rear tire size is 18.4R46.

What is the weight of the tractor?

The weight ranges from 21650 to 23780 pounds.

What is the wheelbase of the tractor?

The wheelbase is 118.9 inches.

A Comprehensive Review of the John Deere 8420 Farm Tractor

A Powerhouse from John Deere

The John Deere 8420 is a row-crop tractor manufactured by John Deere, a renowned name in the agricultural industry. Produced in Waterloo, Iowa, USA, this tractor is a part of the 8020 Series and comes in two variants: wheeled and crawler.

Key Features at a Glance

The tractor boasts an impressive gross engine power of 284 hp and a net engine power of 270 hp. It features a 16-speed full power shift transmission and has a 4×4 MFWD 4WD chassis.

Performance Metrics

The 8420 delivers exceptional performance with its hydrostatic power steering and hydraulic wet disc brakes. It has a tested drawbar horsepower of 207.49 and a PTO horsepower of 269.41, making it a powerful choice for various farming tasks.

Noteworthy Features

The tractor comes standard with a cab and has a hydraulic system capacity of 37 gallons. It also features a closed center pressure-flow compensated (PFC) hydraulic system.

Reliability Factors

John Deere is known for its reliable machinery, and the 8420 is no exception. With its robust engine and durable build, it is designed to withstand the rigors of farming.

Is It Worth the Investment?

Considering its specifications and features, the John Deere 8420 offers good value for money. It competes well with other models in the market in terms of power, features, and reliability.

Pros and Cons

  • Pros: High engine power, multiple transmission speeds, reliable performance, and durable build.
  • Cons: May be on the expensive side for some, and its weight could be a concern for certain applications.

Ideal Work Conditions

The tractor is best suited for row-crop farming and can handle various terrains. Its high lift capacity makes it ideal for heavy-duty tasks.

The Final Take

The John Deere 8420 is a robust and reliable tractor that offers a range of features and high performance. If you’re looking for a tractor that combines power, versatility, and reliability, the 8420 is a strong contender.