The Simplicity MFR #990175 snowthrower was the first type made for riding tractors. It was an evolution of the snowthrowers used on their walking tractors. It used three drive belts and required the operator to go to the front of the tractor to engage or disengage the clutch for the snowthrower
By the late 1960's the snowthrower had been enhanced significantly. It now uses a single drive belt and can be engaged or disengaged from the driver's seat. This A-C MFR 2029938 is a popular example of this fine snowthrower.
This supplement to the owner's manual for the first single belt snowthrowers describes how to adjust it for maximum effectiveness. Note the difference between the MFR #2025057 shown here and the the later 2929938 shown just above. View specifications for the
See parts breakdowns in the Parts section for more info on these earlier snow throwers.