I have an 84 733 and had a complete 15 qt trans oil change. (Jiffy Lube ) You may think changing the trans oil 2 or 3 times will get it "clean" but don't bet your tranny on it.After seeing the color of the ATF that came out, it blew me away. I also had it done to my 85 524td w/310k miles and my 86 735i. I's $80. well spent.My 84 is for sale.