Knudson Tractors

In 1967 a young farmer from Crosby, North Dakota by the name of Jerome Knudson began building his own four wheel drive farm tractor. Many four-wheel-drive tractors that were being built at the time used articulated steering. That is, they had two non-steering axles on a frame that would bend in the middle to steer. Jerome decided to go a different route with his tractor. He used two steerable axles on a rigid frame with the front axle mounted on a separate framework that would allow it to oscillate, or pivot up and down which would keep all four wheels in contact with the ground when going over obstacles. He found a 743 cubic inch 220 horsepower Cummins diesel engine from a truck to power his tractor with. A 5 speed Spicer transmission was mated to the back of the engine and that connected to a 2 speed Rockwell transfercase, giving a total of ten forward speeds. The axles were also built by Rockwell and had outboard planetary hubs which reduced the torque load on the drivetrain. These types of axles were found on heavy equipment such as wheel loaders, commonly referred to as payloaders.

In 1967, very few tractor manufacturers were offering factory built cabs, and those that were available were usually very dirty, noisy, hot in the summer and cold in the winter. Along with the aftermarket tractor cabs of the time, they were a very primitive form of protection from the elements. Many farmers at the time actually scoffed at the idea of having cabs on their equipment. To many, they were seen as an unnecessary luxury. However, Jerome Knudson is a very forward thinking individual that realized that with a quieter, more comfortable workplace, he would be less fatigued and therefore, be more productive by being able to work longer hours. He put a great deal of thought into the construction of his tractor cab. First of all, he built it as a completely separate structure, rather than just adding panels here and there to the frame of the tractor to make an enclosure. Secondly, he mounted the cab to the tractor frame with rubber mounts to reduce vibration and decrease noise. No manufacturers were doing that at the time. Inside the cab, he added heavy insulation to absorb noise. He also designed his own seat with large armrests that allowed the operator to sit sideways in the seat with his or her legs under the armrest.  One of the most notable features of his cab design though is the fact that it was built with over six and a half feet of inside height. This allowed the operator to stand up and stretch occasionally while doing fieldwork.

Jerome was only 23 years old when he completed his new tractor by the summer of 1968. In the field, it performed exceptionally well. The front wheels were steered by the tractors steering wheel and the rear wheels were steered by a separate hydraulic lever. The independent front and rear steering allowed for a multitude of maneuvers to be performed in order to dodge obstacles or to prevent side drift on hillsides. For comparison, with an articulated tractor, when you turn the steering wheel to move away from an obstacle, such as a neighbors sunflower field, the rear wheels of the tractor and the implement attached to it actually move toward the obstacle. (Ask me how I know). With the independent front and rear steering, the rear wheels of Knudson’s tractor could be steered away from the obstacle, and both axles could also be steered in the same direction, known as crab steering, which puts the front and rear wheels in a different track.

Jerome painted his new tractor red, but he later decided to change the color as Versatile tractors had just come on the market and they were red, and International Harvester had changed the color of their four-wheel-drive 4100 from yellow to red when they updated it to the 4156. Massey Ferguson had also recently introduced their own four-wheel-drive model 1500 which was also red in color. He decided to repaint his tractor green and white, but he didn’t want it to look like a John Deere or Oliver or Steiger, so he used a shade of dark green from a Mack truck. This tractor served him well and is still in use on the Knudson farm, however, he did replace the original engine with a 250 horsepower 855 cubic inch Cummins engine.

In 1972, Jerome built his second tractor. This one used the same design as the first, but with a bit more power squeezed from the 855 Cummins. This engine was rated at 335 horsepower, a very powerful engine in 1972. Jerome Knudson had gained a reputation around Crosby as a very respected mechanic and the performance and durability of his tractors were seen by neighbors who were in the market for larger tractors themselves. Soon, he found himself in the tractor manufacturing business. He decided to manufacture two models for sale. They were both very similar and shared most components with each other. The smaller of the two models had an 855 Cummins set at 310 horsepower and the larger one had an 855 set at 360 horsepower. If a manual transmission was preferred by the customer, it was built with a 6 speed Spicer rated to withstand 1200 lb-ft of torque. The power was then transmitted to the axles through a 2 speed Rockwell transfercase. If the farmer preferred a power shift transmission, it would be supplied with a 6 speed transmission/transfercase combination built by Twin-Disc.

One of the most significant features of these new tractors transpired from a chance encounter with a gentleman when Jerome was showing the amount of front axle oscillation at a farm show in Pomeroy, Washington in 1974. This individual saw the front wheel up on a block while the rest of the tractor remained level. Upon seeing this, the gentleman commented that it must be a self-leveling tractor. This comment planted the seed in Jerome’s mind that he could, in fact, build a self-leveling tractor. He just had to build a subframe for the rear axle like the one on the front axle. Of course, both axles couldn’t float freely or the frame of the tractor would just tip to one side and stay there. However, by attaching hydraulic cylinders to the rear axle, the amount of oscillation could be easily controlled. Hillside combines had been around for many years and they employed a mercury switch control that was developed by Raymond Hanson. As the machine would begin to tip sideways, the mercury in the circuit board would stay level, which would close a circuit, sending an electrical current to the electric-over-hydraulic valve, thus forcing hydraulic pressure to the cylinders, keeping the machine in a level state. This not only provided for greater operator comfort, but it also maintained the proper oil level in the engine and transmission as well as keeping the center of gravity where it needed to be by adding weight to the upper wheels to prevent tipping. Jerome received a patent for his innovative hillside feature in about 1976. Coupled with the crab steer capability, this new tractor was well suited to extremely hilly land, such as the Palouse region of Washington along with other areas of the Pacific Northwest. The hillside control could also be manually overridden. This proved beneficial if the tractor was equipped with a dozer blade. By simply tipping the tractor and blade at an angle, it could be used for making a ditch.

Being a mechanic and a farmer, Jerome knew that he wanted his tractors to be easy to service. Much care was put into the design of components so as to allow for future repairs. The cab was built with threaded inserts in the ceiling for attaching a lifting device for removing the transmission or transfercase. Also, the dash could be swung to the side for more room while working inside the cab during transmission removal. The nose of the tractor also had provisions for lifting hooks so the entire structure housing the radiator, coolers and batteries could be removed as one unit. The fuel tank was built the same way. This also allowed for greater flexibility in the manufacturing of the tractors as well. Components could be built individually and then assembled. Jerome Knudson built 22 tractors in his farm shop before selling the patent and manufacturing rights, as well as the Knudson name and logo, to Allmand Brothers from Holdrege, Nebraska in the late 70’s. They kept the same basic design and the hillside feature, but they completely restyled the tractor and changed the color to yellow. It’s unknown exactly how many of these tractors were built, but it’s believed that approximately 35 were built before production ended due to the decline of the 1980’s farm economy.

When I was young, I found a sales brochure for the green Knudson tractors that were built in Crosby in my dad’s collection. I was fascinated by the features that it had and I also thought it was a very stylish tractor as well. I had always wished that my dad would have bought one as it would have been way more unique than the Versatile that we had.

Doug and Carolyn Graupe of Crosby own Long Creek Toys and produced many 1/64 scale models of the green Knudson tractors as well as many other lesser known tractors. Doug was also the second largest shareholder and on the board of directors for Knudson tractors.

Jerome and his sons still farm with some of the tractors that he built. He has a 360 model that has been turned up to 410 horsepower. This tractor is starting its 41st year of doing heavy field work pulling chisel plows and it also does all of his seeding pulling a 60 foot air seeder at 6.2 MPH. He and his sons have also bought back a couple of other green Knudson tractors that he built, as well as a yellow model built in Nebraska.  Several  Knudson tractors are still in use by other farmers as well. It’s a testament to the durability of the machines that Jerome designed so many years ago.