The automatic transmission on most BMWs is said to have lifetime fluid... we here at ECS as well as many transmission manufactures recommend service every 30k miles.

Over the life of a vehicle, the transmission can often be overlooked when performing routine maintenance. If left unserviced, the automatic transmission fluid will break down, causing the valve body and filter to become contaminated with deposits and sludge. This will lead to poor shifting, slipping, and ultimately transmission failure.

Below is a DIY video explaining the Automatic Transmission Service process


Protect your transmission.