Annually or every 20,000 km.
There is an oil filler/measurement plug on the transmission that must be removed to check the oil level. If the vehicle is raised to allow access to this plug, make sure it is securely supported - do not crawl under a vehicle that is supported only by a jack!
To check the oil level correctly, the vehicle must be supported level.

1. Remove the transmission plug, insert your little finger into the plug hole and feel the oil level. It should be near the very bottom of the plug hole.
2. If this is not the case, add the specified amount Table of sizes and adjustment data at the end of the Manual oil through the hole in the plug using a syringe until the oil starts pouring out of the hole. The type of oil is specified in p. Types of lubricants and fluids used in Table of sizes and adjustment data. On some recent models, manual transmissions are filled with automatic transmission fluid. These transmissions usually have a symbol next to the filler/level gauge cap. If you are still unsure, check with your dealer service department.
3. Install the plug and tighten it securely. After a few kilometers, check for fluid leaks.
4. If you notice that your transmission requires frequent topping up, this may only be due to leaks that should be identified and fixed before serious problems arise.
[The original article is located on: «bmwman.ru»]
