Quote Originally Posted by Eggman View Post
I can't speak for Top_Fuel but other forum members have reported improved shifting in the F5MDB manual transmission by replacing the fluid. The most positive reports have come from users who switched to Redline MTL 75W80 GL-4 synthetic.
I think its a placebo. I changed my transmission fluid using the Red Line stuff at 200k miles. I wasn't having any problems. I simply did it as part of my 200k mile maintenance. I notice no notable difference in shifting. The car shifted fine before and the shifts fine today.

I'll probably change the fluid every hundred thousand miles going forward but only as maintenance.