Here’s something you’ve (probably) never seen before: An Allis Chalmers D-21 with Front-Wheel Assist!


This tractor was custom-made by Ted and Hans VanValkenburg. Ted and his son Hans are from upstate New York. They’ve been Allis-Chalmers enthusiasts for a long time, and they’re always up to a new challenge! Here’s the story of this unique tractor.


They found this D-21 sitting outside an airport hangar. It was a single-owner machine, but it had been neglected and was in non-working condition. Ted and Hans decided to restore it into good working order. After rebuilding the engine, they were up for another challenge: Front-Wheel Assist.

Ted and Hans aren’t the first people who have thought it would be cool to have FWA on a D-21. The Allis Chalmers company produced 10 hydraulic FWA tractors themselves back in 1967. Rumor has it that 9 out of 10 were turned back into the company, and no one knows what happened to the remaining one. It’s an intriguing mystery!


This tractor isn’t the legendary 10th factory original FWA – but the addition looks so good you’d never know the difference! Instead of making the conversion with aftermarket parts, Ted and Hans went all out. They built the FWA exclusively with authentic AC parts. I’d bet it could even fool an Allis-Chalmers Engineer!

The first step in adding the FWA system was finding a tractor to serve as a “donor.” Ted and Hans uncovered a good (but not perfect) fit in a hydraulic FWA system on a Model R66 Gleaner AC combine. Once they got the parts, they needed to figure out how to fit them onto the D-21 tractor.


Getting the hydraulic flow right turned out to be the hardest part of the job. (Maybe this is where Allis-Chalmers had trouble back in the 60s?) Ted and Hans kept at it. They collaborated with 3 other men and spent a total of 200+ hours figuring out how to get the flow valve right to properly circulate the oil. After a lot of hard work, they got it right – wow!  

Ted and Hans completed this project back in 2015. Since then, it’s continued to operate perfectly. They haven’t taken it to many shows yet, but who knows – maybe it will appear at a show near you next summer! Thanks for sharing, Ted and Hans, and great job!