ok i have a hatch b16 sir 2 and when i did the swap i couldn't find a good source for what kind of fluid to put in it so i just decided to talk too a local mechanic and put in some 30 weight motor oil but when i slam 3rd and now 4th gear it grinds in i talked to a friend that drives a sentra he uses shock proof tranny fluid additive more or less what i'm asking is what is the best tranny fluid for b series (please include weight) and are there any good additives for honda

 

Honda's are very picky about what fluids work well for them. The only good stuff you can run in them is what Honda makes. Go to the closest Honda dealership and buy it from them. Using motor oil in the transmission will lead to rougher shifts.