CVT Transmission Maintenance
by Ian Kenney
Continuously variable transmissions (CVTs) have been around since the late 1800s, and were widely used throughout the 20th century in farm equipment and riding mowers. In the 21st century, automakers in pursuit of greater fuel efficiency turned to CVTs which have fewer moving parts, and thus less friction, than their step-transmission counterparts.
Basics
Traditional passenger car transmissions are like a multispeed bicycle. A series of gears that step up in size alters the gear ratio so the engine is turning at the optimum speed for the conditions. CVT dispenses with the gaps between gears, using a pulley or chain system to continuously alter the ratio so the engine is always turning at peak performance levels.
Durability
Nissan is a big supporter of the technology, installing CVTs into four different models as of 2011. In 2010, Nissan preemptively extended the warranties on those transmissions to help allay consumer fears about durability issues.
Maintenance
CVTs use a system of hydraulics to manage the intense pressures placed on the pulleys and this fluid must be changed regularly. Nissan recommends fluid changes every 15,000 miles. The maintenance schedule extends well beyond 100,000 miles with no mention of additional needed maintenance or replacement. According to Edmunds.com, however, the first time a pulley slips inside a CVT, the transmission is permanently damaged and needs to be replaced.
