Production years
1963-1969
Allis-Chalmers tractor ยท 1963-1969
Allis-Chalmers D21 Tractor
The Allis-Chalmers D21 is a large, 100-plus-PTO-hp 2WD row-crop tractor built for serious draft work. It was Allis-Chalmers' first tractor rated above 100 horsepower.
Engine
Allis-Chalmers 6-cylinder, 7.0L diesel
Power
103 hp claimed PTO; 93 hp claimed drawbar
Weight approx.
9,500 lb
Allis-Chalmers D21 specifications
| Production years | 1963-1969 |
|---|---|
| Engine | Allis-Chalmers 6-cylinder, 7.0L diesel |
| Power | 103 hp claimed PTO; 93 hp claimed drawbar |
| Transmission | 8-speed sliding gear |
| Weight approx. | 9,500 lb |
| Fuel type | Diesel |
| Drive and steering | 2WD with power steering |
| PTO | Independent 1,000-rpm rear PTO |
What the D21 is used for
The D21 was designed for heavy tillage and large implement work, with power appropriate for seven-bottom-plow-era fieldwork. Its size and 2WD configuration favor open ground and operators comfortable with vintage high-horsepower tractors.
It can also be a compelling show, parade, or collection tractor, especially when kept close to original specification. It is less convenient for tight loader work or jobs where modern cab comfort and four-wheel drive are important.
Why the Allis-Chalmers D21 stands out
A 7.0L diesel, 103-hp claimed PTO output, independent 1,000-rpm PTO, and 9,500-lb operating presence define the D21. The 1965 Series II update began at serial number 2130, an important distinction for collectors and buyers.
Buying a used Allis-Chalmers D21
Identify whether the tractor is a Series I or Series II from its serial number, then inspect the engine, 8-speed transmission, brakes, and steering under operating temperature. Verify that the independent 1,000-rpm PTO engages correctly and assess rear tires and ballast, which materially affect the cost and usability of a D21.
Allis-Chalmers D21 frequently asked questions
How much PTO power does an Allis-Chalmers D21 have?
The D21 has a claimed 103 hp at the PTO.
What engine is in the D21?
It uses an Allis-Chalmers 7.0L six-cylinder diesel engine.
What is the difference between D21 Series I and Series II?
The upgraded Series II began at serial number 2130 in 1965.
Specifications are commonly cited figures for general reference; exact figures vary by year and serial number, so confirm against TractorData.com and the machine's records. Values and prices of used tractors vary by condition and region. Page updated Aug 4, 2026.