John Deere 8420

Last Updated: July 2024

Overview

The John Deere 8420 is a large, powerful row-crop tractor designed for various agricultural tasks. It features a 496 cubic inch, six-cylinder turbocharged diesel engine producing 270 horsepower at 2200 RPM. The engine has a bore of 4.56 inches and a stroke of 5.06 inches. It has a 16-speed full power shift transmission and hydrostatic power steering. The rear tire diameter is 480/80R46, and the operating weight is 23,955 pounds without ballast. The tractor can exert a maximum force of 17,897 pounds through the hydraulic system's whole range, with a pump delivery rate of 42.2 GPM at maximum hydraulic power of 60.4 HP. The maximum torque is 823 lb.-ft. at 1200 RPM, with a torque rise of 46.6% and 32% at 1800 RPM.

Key Specifications

Category: Row Crop

Power Output: 270

Transmission: Full power shift

Drive Type: 4WD

Operating Weight: 23955

Fuel Type: Diesel

Image Gallery

John Deere 8420 Tractor

John Deere 8420 vs. Similar Tractors

Power Output

Above Average

Greater than 85% of similar tractors.

Hitch Capacity

Below Average

Greater than 23% of similar tractors.

Operating Weight

Above Average

Greater than 77% of similar tractors.

Technical Specifications

Engine

Manufacturer: John Deere
Model: -
Cooling Type: Liquid-cooled
Cylinder Orientation: Inline
Valve Configuration: -
Fuel Type: Diesel
Induction Type: Turbocharged
Cylinders: 6
Displacement (ci): 496
Bore (in): 4.56
Stroke (in): 5.06
Rated RPM: 2200
Power Output (hp): 270

Transmission

Type: Full power shift
Forward Gears: 16
Reverse Gears: 4
Total Gears: -

Dimensions

Length (in): 211.9
Width (in): -
Height (in): 122.2
Operating Weight (lb): 23955

Power Take-Off (PTO)

PTO Type: Independent with hydraulic wet discs clutch
PTO Speed 1 (rpm): 1000
PTO Speed 2 (rpm): 540/1000
PTO Speed 3 (rpm): -

Miscellaneous

Chassis: 4x4 MFWD 4WD
Drive Type: 4WD
Steering Type: Hydrostatic power
Coolant Capacity (qts): 35.9
Front Tire Diameter (in): 30
Front Tire Width (in): -
Rear Tire Diameter (in): 480/80R46
Rear Tire Width (in): -
Front/Rear Rim Diameter (in): -
Tire Type: Ag
Manufacture - End Year: -
Hitch Type: III/IIIN
Hitch Category: Category 3
Hitch Position: Rear
Hitch Capacity (lb): Up to 17,300 lbs
Operator Station Type: Cab (standard)
Starter Type: Electric
Brake Type: Hydraulic wet disc
Hydraulic System Type: Closed center pressure-flow compensated (PFC)

Test Results

Nebraska Tractor Test Laboratory - Test Dates: May 7 to May 31, 2002

Maximum Power and Fuel Consumption

Maximum Power: 269.41 HP (200.90 kW) at 2000 rpm
Fuel Consumption at Maximum Power: 14.47 Gal/hr (54.77 l/h) with a fuel efficiency of 0.378 lb/hp.hr (0.230 kg/kW.h)
Rated Engine Speed (PTO speed—1009 rpm): 235.45 HP (175.58 kW) at 2200 rpm with a fuel efficiency of 0.409 lb/hp.hr (0.249 kg/kW.h)

Drawbar Performance

Power at Maximum Pull (8th Gear): 207.49 HP (154.73 kW) with a drawbar pull of 16312 lbs (72.56 kN) and a speed of 4.77 mph (7.68 km/h)
Fuel Consumption at Maximum Power: 0.462 lb/hp.hr (0.281 kg/kW.h) with a fuel efficiency of 15.23 Hp.hr/gal (3.00 kW.h/l)

Torque and Engine Performance

Maximum Torque: 823 lb.-ft. (1116 Nm) at 1200 rpm
Torque Rise: 46.6% with a torque rise at 1800 engine rpm of 32%

Hydraulic Performance

Maximum Force Exerted Through Whole Range: 17897 lbs (79.6 kN)
Pump Delivery Rate at Maximum Hydraulic Power: 42.2 GPM (159.7 l/min)
Hydraulic Power: 60.4 HP (45.1 kW) at 2455 psi (169 bar)

Tractor Weight and Ballast

Unladen Tractor Mass with Ballast: 30500 lb (13835 kg)
Unladen Tractor Mass without Ballast: 23955 lb (10866 kg)

NTTL.(2002). Nebraska Tractor Test 1800 for John Deere 8420 Diesel 16-Speed. Lincoln, NE: Nebraska Tractor Test Laboratory. Retrieved from https://digitalcommons.unl.edu/tractormuseumlit/2176