Necessary Properties of ATFs

"Fully automatic transmissions create a different set of requirements for lubrication," says Mark Betner, Mystik Product Manager, CITGO. "The automatic transmission is more complex in that it includes different gear sets and clutch plates controlled by a valve body, which routes the transmission fluid to different gear sets as the engine speed increases. This, of course, is done automatically once the operator moves the shift lever into position." According to Betner, an automatic transmission fluid must: 

  • Prevent wear.
  • Maintain viscosity over a long service life and in some cases severe operating conditions such as heavy stop and go, heavy loads or trailer towing.
  • Resist fluid breakdown due to high operating temperatures which can cause excessive buildup of carbon material on clutch plates. This results in transmission slippage and can lead to eventual transmission failure.
  • Control buildup of deposits on critical components such as the valve body and clutch plates.
  • Maintain fluidity over a wide temperature range.

"Always consult with your lubricant supplier and equipment manufacturer to learn as much as possible about the products," says Betner. "Know there are multiple levels of lubricant available and the transmission is often the neglected component, as many equipment owners focus on engines and forsake transmission maintenance and lubricant facts.

"Think about this: how often are automatic transmissions rebuilt compared to engines? It is worth learning more about transmission lubrication."