Recently my car has been shifting roughly and at random times. My haynes manual says to replace the fluid and filter to fix the problem . A few people have been telling me that this will most likely hurt my transmission. if so i won't bother with it. My tranny is a 4r70w with 50k miles on it. So would changing these things solve my problem or hurt me in the long run?

also i bought the car at 45k miles and i don't beleive the tranny fluid and filter have been changed before.

edit: would royal purple max atf be good to use for the fluid

 

I doubt it. Usually flushing the fluid under pressure can hurt a high milage trany. But just changing the flid and filter shouldn't hurt anything. In fact I fixed a chatter in my torq converter by changing the fluid. Mine has over 160k and runs smoother than ever now. Make sure you drain the torq converter as well to get all of the old fluid. That will make a difference of about 8 quarts.