Most UTVs are equipped with some variation of the continuously variable belt drive transmission (CVT). This transmission relies on centrifugal force to vary the effective “gear” ratio between the drive pulley and driven pulley. These types of transmissions are well-proven, lightweight and relatively inexpensive. In some cases, they require adjustment and/or occasional belt replacement, and if the belt gets wet, it may slip, resulting in a loss of power to the wheels, but even this is a rare situation with most models. Transmission housings are designed to prevent water infiltration to avoid that situation when fording.
When the CVT is coupled to a high-low-reverse gear transmission, you have the best of both worlds. Extend it further to a host of four-wheel-drive systems and locking differentials, and you will have a difficult time figuring out how to run out of traction.
A number of heavy-duty UTVs are equipped with hydrostatic transmissions of similar design to those found in compact tractors and industrial equipment. These transmissions are also continuously variable but operate on the principle of high-pressure hydraulic oil pumped at varying rates through a hydraulic motor(s), which in turn spins the wheels either directly or more likely through a conventional driveline that may include a high-low transmission as well as selectable four-wheel-drive. UTVs equipped with hydrostatic transmissions tend to have lower maximum speeds than those with CVTs, but there is little maintenance other than changing the hydraulic fluid and filters as recommended. In addition, since these UTVs are already equipped with a robust hydraulic system, they can be more easily fit with hydraulic dumping beds and auxiliary hydraulic ports to power attachments and the like.
Interested in more on UTVs? Check out Electric Polaris UTV a Choremaster.
Hank Will raises hair sheep, heritage cattle and many varieties of open-pollinated corn with his wife, Karen, on their rural Osage County, Kansas farm. His home life is a perfect complement to his professional life as editor in chief at GRIT and Capper's Farmer magazines. Connect with him on Google+.