Allis Chalmers HD21

The Allis Chalmers HD21 is a tractor produced by Allis Chalmers. It is equipped with a 844 ci 13.8 L engine. The rated power output is 225 hp 167.8 kW. Transmission: 2 forward and 1 reverse. Drive type: crawler. Operating weight: 45500 lbs 20638 kg.

Overview

	1954 - 1965 Model year 1954-19581958-1965 Agricultural Crawler tractor
1954 - 1965
Model year 1954-19581958-1965
Agricultural Crawler tractor

Production
Manufacturer	Allis Chalmers
Agricultural Crawler tractor
Built in Springfield, Illinois, USA

Allis Chalmers HD21 Engine
Allis-Chalmers 13.8L 6-cyl diesel
Fuel tank	135 gal 511.0 L
Engine details ...

Allis Chalmers HD21 Transmission
2-speed torque converter
Transmission details ...

Allis Chalmers HD21 Power
Engine	225 hp 167.8 kW
Drawbar (tested)	135.12 hp 100.8 kW
Performance test details ...

Mechanical
Drive	crawler
Contracting band brakes
Open operator station.

Dimensions & Tracks
Weight	45500 lbs 20638 kg
Tracks
Full dimensions and tracks ...

References
Engineering-in-Action published in 1956, by Allis Chalmers

Engine

Engine Detail — 844 ci / 13.8 L Diesel

Manufacturer	Allis-Chalmers
Configuration	6-cylinder, liquid-cooled vertical I-head
supercharged diesel
Displacement	844 ci 13.8 L
Bore/Stroke	5.25x6.50 inches 133 x 165 mm
Power	225 hp 167.8 kW
Air cleaner	oil bath
Compression	13.3:1
Rated RPM	1800
Starter volts	24
Coolant capacity	80 qts 75.7 L

Transmission

Transmission — 2 forward and 1 reverse torque converter

Type	torque converter
Gears	2 forward and 1 reverse

Dimensions

Allis Chalmers HD21 Tracks

Dimensions
Length	198 inches 502 cm
Height	99 inches 251 cm
Weight	45500 lbs 20638 kg

Tests

Nebraska Tractor Test 550
Diesel 2-speed crawler July 6 - 18, 1955 Link: Nebraska Tractor Test 550 file
Drawbar performance
Max power	135.12 hp 100.8 kW
Max pull	40563 lbs 18399 kg

Photos

Allis Chalmers HD21

Allis Chalmers HD21

Allis Chalmers HD21

Allis-Chalmers HD-21 bulldozer

Allis-Chalmers HD-21 bulldozer

Allis-Chalmers HD-21 bulldozer