Family restoration project, Allis Chalmers D-21

This Allis Chalmers D-21 with serial number 1627 was purchased at auction in Brillion, Wisconsin in December of 2023 as a restoration project, for me, my dad and brother to work on. The serial number would indicate it’s a 1964 series one, but having been entirely through the tractor, every other part of the tractor would indicate it’s a series two, from late 1967 or newer.

One major indicator is the main drive gears in the rear end. They are the larger drive gears that the late 1967 and newer models had. The sheet metal, larger radiator, turbo and engine are also indicative of a series two rather than series one. This tractor, as purchased had a welded block, and 34″ rear wheels. A different block was acquired and the engine has been completely rebuilt and is considered (zero time) as all new components were added to the inside. A refurbished injection pump, with larger lines and injectors were added.

Other brand new components include the water pump, hydraulic pump, alternator, starter, power steering valve, hydraulic lines and couplers, wiring harness, all new gauges/panel, steering wheel, seat cushions, front spindles and hubs, new clutch, front and rear rims, and all new rubber.

The PTO clutch was completely rebuilt with new clutch disks and spacers and the three hydraulic cylinders (two lift, one for steering) have been taken apart and re-sealed. The hydraulic spool valve was also taken apart and had new seals and O-rings put in it. In addition to the iconic chrome bars on the front grill and throttle lever, we had some additional components chromed that you don’t normally see.  These items include, all five hydraulic related levers, the air cleaner behind the grill, the steering wheel adjust lever, and the fuel cap.

The project took a year and a half to complete. The three of us all contributed our thoughts, skills and labor toward the project. We also had a lot of other help with many of the components. The tractor resides on the North Haven Farm in Haven(Sheboygan) Wisconsin.

Quentin Mueller
Goldsboro, North Carolina

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