I've hit the 70k mile mark on my e46 and was thinking of getting the tranny fluid changed. It is a 5 speed, and I looked in the manual, and it said that there's no need to change it. It's good for life. I don't know what to think. I was about to go get some redline fluid for it until I saw this. Is this wise, or would I be better off putting redline fluids in the trans. If so, what viscocity and weight and all that good stuff should I put in it. Thanks for the the info.

IMO, it's worth the cost of changing the fluid to not have to worry about something screwing up.

go with the redline..not sure about what weight to go with for your trans though

My mech says the tranny fluid on the E46 doesn't need to be changed. He told me that when I asked about the "lifetime" fluid on my E36.

I recently drained the original oil from my manual tranny (@ 65k miles) and replaced it with Redline MTL and it shifts a lot smoother now. Some people use Redline D4 ATF in their manual transmissions.

NOTHING is lifetime on the car, ever, every fluid will need changing eventually. Especially things that are in contact with high heat areas, like trannys.

Its only "lifetime" while BMW is responsible for changing it which equates to 4 years. Friggin joke.

NO FLUID is lifetime due to viscosity breakdown and contamination from metal shavings and dirt infiltration.

Spend the 60 minutes of time if you DIY and $30 worth of fluid as a new transmission is much more expensive. Not to mention the improved feel of the transmission. Hell, spend the $100 bucks if you pay someone else to do it. Come on, its a BMW, don't skimp on pennies and don't buy into the marketing hype.

True. There has been NO miracle of science and engineering where a company has created lifetime tranny + fluid.