ATF : New complex technologies among automobile manufacturers
The automatic transmission fluid market has developed into a very specialized product market. Over 140 million gallons are used annually for factory-fill ATF in North America alone. It has become a “fragmented market,” meaning each automotive manufacturer is requiring model-specific specifications for automatic transmission fluid.
Multiple specification changes have occurred in the past five years. In 2005 there were approximately 5 transmission fluid types. Today, there are over 15 types, the largest percentage belonging to Dexron VI, Chrysler ATF +4, and several Ford specialty fluids.
What this means to torque converter rebuilders is that they need to be well educated in the proper fluids to go with the appropriate torque converter. Torque converter performance and durability are dependent on the correct fluids. Today’s transmissions are designed for six to eight speeds, as compared to 1980s of the standard three-speed automatic. Modern torque converters face the challenge of higher horsepower and heavier vehicles under severe heat and friction conditions. Driver comfort is required for smooth clutch-on, clutch-off operation. Lubrication of rotating components face grueling stop-and-go traffic. To meet these challenges, each manufacturer has developed its own fluid specifications, so critical that interchangeability is a thing of the past. GM’s Dexron VI is to be used in the 2006 and newer GM vehicles; however, it is not recommended for any CVT transmission equipped vehicles. Dexron VI is a new, low viscosity ATF (5.5-6.3cSt at 100ºC) and retrofits all vehicles that require Dexron III. This fluid is safe for all GM torque converters, except CVT. Ford’s Mercon and Mercon V specification ATF have exclusivity until March 2010. This fluid is still available and is
to be used in Ford transmissions except 5R110, which require a Ford SP designation. Ford SP can also be used in the 6R60 transmission made by ZF. The Mercon SP type fluid has different frictional characteristics than previous Mercon fluids. Mercon SP is similar to Dexron VI and is also a low viscosity fluid. Mercon LV is another stand alone ATF and factory fill for 2008 models, such as the Ford Focus. This new fluid is an intended fill for life. This fluid must be used to prevent torque converter clutch damage and cannot be substituted. Mercon C is designed for Ford CVT equipped vehicles only.
There are currently seven low viscosity ATFs produced by the OEMs. It is critical to use the correct fluid for each designated vehicle to ensure proper transmission and torque converter operation. Do not attempt “multi-vehicle” fluid concepts. One size does not fit all. These lighter weight synthetic-based lubricants offer better fuel economy, heat dissipation, smoother shifting, and longer service intervals. Whenever possible, the converter rebuilder needs to use OEM-type friction liners and seal material to ensure compatibility. Incorrect fluid may result in computer codes and converter failures if not followed closely.
– Found in May 2008 Newsletter