Originally Posted by martinbaltes

after talking to dealers and reading x5 posts, i have decided on 75w90 for the front axle. and 75w140 for the rear axle. however, use a synthetic blend for both and add a container of posi addititive to both axles as well. the transfer case and the power steering pump take dexron3 trans fliud. the auto trans takes an oem specific bmw fliud. do not use anything else. changing trans fluid has been debated. bmw says a lifetime fluid. fluid and or a filter change has caused problems leading to the replacement of the trans.