Blackstone Transmission Fluid Report
A couple weeks ago I decided to have my transmission fluid/filter/pan changed. The vehicle was at about 45,500mi, and I decided to have some preventative maintenance done on it before the warranty was up (also if anything was caught then I could get it covered).
Most of us know that although BMW says the transmission has a "lifetime" fill of fluid, and that it never needs to be changed, that the transmission maker, ZF, recommends replacement at 80,000-100,000km (50-60kmi). For replacement, I ordered the
ZF OEM transmission service kit from FCPEuro.
After having the transmission service done I sent a sample of the fluid to Blackstone to see what the wear looked like, especially since I have a decent amount of track days on the car. There's plenty of data on oil change intervals and track days, but not much on transmission fluid changes since they're done far less frequently or not at all.
With that said, here's my report:
Given the report, it looks like it's a good thing I changed the fluid. My fluid at 45,500mi had the same wear as one that has 72,000mi, or 116,000km. I guess if you have a use case like I do, you should be changing the transmission fluid every 37,500mi.