How does a hydrostatic transmission work?A hydrostatic transmission consists of a variable displacement bi-directional axial piston pump and a fixed (typically) displacement bi-directional axial piston hydraulic motor. The pump is powered by an external power source, usually a v-belt from a gasoline engine. The engine can be operated at its best operating speed while the speed and direction of the vehicle can be regulated with the transmission. As the control handle is moved forward, the swash plate in the pump increases its angle to produce more hydraulic flow to the hydraulic motor, thus increasing the speed. The angle of the swash plate can be manually controlled to provide bi-directional control and variable speed output. For more information, please see the How it Works video in the Learning Center.
How long should my Hydro-Gear unit last?Hydro-Gear products are designed to meet the OEM’s (Original Equipment Manufacturer) specifications. Life expectancy will vary by product, how the product is used, and the quality of maintenance and service during the life of the product. To ensure maximum life please perform all routine maintenance and service items as prescribed by the product’s service manual.
What maintenance should be performed on my Hydro-Gear product?Maintenance procedures will vary by product. Please refer to the service and repair manuals for specific details.
My vehicle seems to have a loss of power. Is the problem with my transmission?This can be caused by a host of items, including loose drive belts, improperly adjusted linkages, low engine speed, etc. Please refer to the service and repair manuals for your product for additional information.
My hydrostatic transmission appears to be leaking. What should I do?Please refer to the service and repair manuals for your product for additional information.
My hydrostatic transmission is noisy. What should I do?Please refer to the service and repair manuals for your product for additional information.
What type of oil should I use in my Hydro-Gear unit?Please refer to the service and repair manuals for your product for additional information.
Can I swap my old hydrostatic transmission to a different model?The OEM selected the proper size hydrostatic unit to meet the requirements of their product. While other Hydro-Gear products may be similar in shape and size there may be substantial internal differences that would impair or damage the unit if substituted. We strongly discourage the use of any model not originally specified by the OEM.
What are the differences between residential and commercial grade transmissions?Commercial grade transmissions are designed to withstand the wear inflicted on them from daily use, often in harsh conditions. Commercial grade transmissions have upgraded components (axles, bearings, etc.) to cope with the larger, heavier commercial vehicles.
What is the difference between an integrated unit and a separate pump and motor?From a performance standpoint there is no difference. Both will perform equally if they have the same displacement. The integrated unit is easier to install for the OEM and has fewer potential leak points. In contrast, the pump and motor allow greater flexibility in mounting locations.