Owners of certain 2004 and newer Toyota vehicles requiring the “WS” automatic transmission fluid spec should heed serious warnings about using aftermarket shops to service and refill their transmissions. Toyota has developed a specific, accurate automatic transmission refill system for these applications called the Toyota Transmission Fill System. Aftermarket shops and do-it-your-selfers not using this system may inadvertently under-fill the transmission, leading to erratic shifting and ultimately, catastrophic transmission failure.

AMSOIL has released a Technical Service Bulletin on this issue: Toyota Transmission Fill System and Aftermarket Transmission Shops. Simply put, if you have a late-model Toyota, have your transmission serviced only by a certified Toyota dealer or an approved shop using the Toyota-specific Transmission Fill System. AMSOIL offers an outstanding replacement fluid for Toyota’s requiring the “WS” ATF spec. Toyota owners looking for a synthetic upgrade over the OEM fluid can bring the AMSOIL Synthetic Low-Viscosity Automatic Transmission Fluid to their dealer. This Toyota “WS” compatible product offers outstanding performance and wear protection under even the most severe conditions.