Simple transmission question
I recently purchased a 2001 325ci with 165000 km or roughly 100000 miles. Ive read a few posts on this, but I'm still not sure. I know that the transmission oil has been changed once, but I don't know when it was changed. Ive read that once the oil has turned into some kind of sludge that its pretty much holding the transmission together and once the tranny fluid is changed, the transmission usually fails. Is this true?
I was planning on changing the transmission and differential sometime within the next two weeks. Is this not a good idea? As crazy as it sounds, is it actually a better idea to leave the fluid in the transmission?