About the Allis-Chalmers D21
The D21 was introduced in 1963 as the largest tractor in the D Series. It used a large six-cylinder diesel, power steering, an independent 1,000-rpm PTO, and the size and weight needed for large field work.
The D21 was built from 1963 through 1969 in Series I and Series II versions. The serial number table shows the change from Series I to Series II during the 1965 production run.
Serial Number Reference
Serial number locations: The tractor serial number is stamped on the left side, on the front flange of the torque housing near the starter mounting. The engine serial number is stamped on a plate at the upper rear of the engine block on the left-hand side.
The table below shows the beginning tractor serial number for each Model D21 year and series:
1963-1965
| Model D21 year |
Beginning serial number |
| 1963 - Series I |
100 |
| 1964 - Series I |
1,417 |
| 1965 - Series I |
2,079 |
1965-1967
| Model D21 year |
Beginning serial number |
| 1965 - Series II |
2,130 |
| 1966 - Series II |
2,408 |
| 1967 - Series II |
2,863 |
1968-1969
| Model D21 year |
Beginning serial number |
| 1968 - Series II |
3,777 |
| 1969 - Series II |
4,498 |
1963-1965
| Model D21 year |
Beginning serial number |
| 1963 - Series I |
100 |
| 1964 - Series I |
1,417 |
| 1965 - Series I |
2,079 |
| 1965 - Series II |
2,130 |
1966-1969
| Model D21 year |
Beginning serial number |
| 1966 - Series II |
2,408 |
| 1967 - Series II |
2,863 |
| 1968 - Series II |
3,777 |
| 1969 - Series II |
4,498 |
1963-1969
| Model D21 year |
Beginning serial number |
| 1963 - Series I |
100 |
| 1964 - Series I |
1,417 |
| 1965 - Series I |
2,079 |
| 1965 - Series II |
2,130 |
| 1966 - Series II |
2,408 |
| 1967 - Series II |
2,863 |
| 1968 - Series II |
3,777 |
| 1969 - Series II |
4,498 |
Total production: 2,409 Model D21 tractors.
Allis-Chalmers D21 Paint Reference
For restoration planning, the Allis-Chalmers D21 is listed in the Allis-Chalmers tractor paint guide with the original paint references below.
Allis-Chalmers D21 paint reference by production period
| Production period |
Metal |
Wheels |
Disc |
Chassis |
Trim |
| 1961 through 1977 |
Persian Orange 2 |
Cream, Persian Orange 2 |
Cream, Aluminum |
Persian Orange 2 |
Cream, Chrome grille |
Paint placement can vary by production year, series, and equipment configuration.
