BMW E39 automatic transmission (5HP) oil change
Does the E39 automatic transmission oil need changing?
BMW treats the oil as lifetime fluid and there is no official change interval. This does not forbid changing it, but BMW does not recommend it. Under heavy use, for example constant caravan towing, a change every 150 000 km has been recommended. Opinions on the benefit of a change vary.
How is a 5HP automatic oil change done?
Just draining the oil pan replaces only about a third of the oil. A full change is done by flushing until the oil coming out is red, and the filter is changed at the same time. A change done correctly does not shorten the life of a healthy transmission, but it is not worth trying to revive an already faulty transmission with it.
Which filter and pan gasket fit the ZF 5HP18 transmission?
The filter part number is 19-0266 (5-speed 5HP18; does not fit the HP30 transmission). The pan gasket part number is 19-0267, and the oil pan has 16 bolts.