John Deere industrial tractors

John Deere 644A

The John Deere 644A is a wheel loader manufactured by John Deere from 1971 to 1973. It features a turbocharged 6-cylinder 6.6L diesel engine producing 141 hp gross and 131 hp net. The loader has a 4-speed power shift transmission with torque converter and articulated power steering. It includes hydraulic wet disc brakes and a cab with heat as standard. The 644A has a wheelbase of 104 inches, operating weight of 26472 lbs, and uses industrial tires sized 20.5-25 or 17.5-25. The front-end loader attachment offers a breakout force of 23944 lbs, 45° dump angle, and a bucket width of 104.6 inches. It was succeeded by the John Deere 644B model produced from 1974 to 1980.

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Model644A

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Technical Specifications

Detailed specifications and technical data for John Deere 644A

Power

Engine (net)	131 hp (97.7 kW)
Engine (gross)	141 hp (105.1 kW)

Tires

Industrial rear	20.5-25, 17.5-25
Industrial front	20.5-25, 17.5-25

Engine

Type	turbocharged diesel, 6-cylinder, liquid-cooled
Model	John Deere 6.6L 6-cyl diesel
Torque	345 lb-ft (467.8 Nm)
Starter	electric
Fuel tank	50 gal (189.2 L)
Rated RPM	2400
Torque RPM	1600
Bore/Stroke	4.25x4.75 inches (108 x 121 mm)
Compression	16.5:1
Power (net)	131 hp (97.7 kW)
Displacement	404 ci (6.6 L)
Oil capacity	17 qts (16.1 L)
Power (gross)	141 hp (105.1 kW)
Starter volts	12
Coolant capacity	36 qts (34.1 L)

Height

Cab	127 inches (322 cm)
ROPS	122 inches (309 cm)
Exhaust	117 inches (297 cm)

Dimensions

Length	247.8 inches (629 cm)
Wheelbase	104 inches (264 cm)
Rear tread	80 inches (203 cm)
Front tread	80 inches (203 cm)
Ground clearance	15.9 inches (40 cm)
Operating weight	26472 lbs (12007 kg)

Electrical

Batteries	2
Battery volts	12
Charging system	alternator

Hydraulics

Type	open center
Pressure	2250 psi (155.1 bar)
Pump flow	60 gpm (227.1 lpm)
Steering flow	27 gpm (102.2 lpm)
Steering pressure	2000 psi (137.9 bar)

Mechanical

Cab	Cab standard with heat
Drive	Four-wheel drive
Brakes	Hydraulic wet disc brakes
Steering	Articulated power steering
Final drives	inboard planetary

Production

Type	Wheel Loader
Years made	1971 - 1973
Manufacturer	John Deere

Attachments

Type	front-end loader
Dump angle	45°
Bucket width	104.6 inches (265 cm)
Reach (dumped)	34.75 inches (88 cm)
Height (at pin)	142 inches (360 cm)
Clearance (dumped)	110.5 inches (280 cm)
Loader breakout force	23944 lbs (10860 kg)
Rollback (ground line)	42°