As of right now the tranny makes a sound after it heats up but I guess when I bought it it hasn't been changed cuz of BMW and their lifetime fluid statement cuz I got the car around 2008 from the Dealer and it had gone through a full engine rebuild but I don't know about the tranny so that's why I'm thinking of changing in the beginning because of the noise and when in drive the car roles a lot slower then in nutural and makes noise on drive and not on nutural.