Automatic transmission fluid

From Wikipedia, the free encyclopedia

Automatic Transmission Fluid (ATF) is the fluid used in vehicles with a self shifting or automatic transmissions. It is typically colored red to distinguish it from motor oil and other fluids in the vehicle. Its level is checked with a dipstick while the engine is running.

The fluid is a highly refined mineral oil optimised for the special requirements of an automatic transmission, such as valve operation, brake band friction and the torque converter as well as gear lubrication.

ATF is also used in most power assisted steering racks.

There are a number of specifications for ATF, such as GM DEXRON II, and the vehicle manufacturer will recommend which must be used.