I have heard coolant every 4 years, brake fluid every 2 years from my dealer. I have never even heard of a dealer recomending a tranny fluid change (it's "lifetime"). I do mine more often than that though, as a guidline always at least FOLLOW dealer reccomendations. Tranny fluid should probably be done maybe 50K-60K (Mine was black at 90K). Not changing the coolant, brake fluid, and tranny will eventually destroy the components that ened these fluids (tranny is widely documented, with auto at least). Tranny and Coolant get dirty and the brake fluid accumulates moisture or air (forgot which, causes spongy pedal).Just curious- why is it so important to change the tranny fluid and coolant , including brake fluid so soon ( every two years or so ) This is what the dealer recommends. But is it really needed every two years ? what are your thoughts. If this is the case, let me know what negative experiences some of you have had from NOT changing these fluids. Thanks for the input.