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.
4,310 kg
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. | 4,310 kg |
| 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-plough-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 tyres 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. Used tractor values vary by condition and region. Page updated 19 Sep 2026.