In the 1980's, Sauer-Danfoss (formerly Sauer-Sundstrand) in Ames, IA, produced a hydraulic transmission that was paired with an axle assembly at the OEM.
Agri-Fab in Sullivan, IL, produced an axle assembly that was paired with a transmission at the OEM.
Hydro-Gear was founded in 1991 as a joint venture. The initial goal was assembling the transmission and axle combination prior to supplying the OEM. What has resulted is a company with the most repeat customers in the industry.
Today, Hydro-Gear is one of the world's preeminent designer and manufacturer of hydrostatic transmissions, serving multiple industries and exporting product worldwide.

Headquartered in Sullivan, IL, Hydro-Gear is a global leader in the design and manufacture of precision drive systems. Working in partnership with OEMs worldwide, Hydro-Gear produces an extensive line of high-performance, efficient hydrostatic transmissions and transaxles; gear reduction drives; variable displacement piston pumps and wheel motors; electric drive systems, and infinitely variable transmissions for industrial, commercial, and consumer markets. With multiple manufacturing sites and global operations, Hydro-Gear’s goal is to ensure our products and services meet our customers' rigorous requirements and exceed their expectations.