manual transmission fluid

[BoostedAWD]

Im planning on changing my trans fluid on my 03 p5 tomorrow because god knows when the last time it was changed. I read that I need 75w90 in GL4 because gl5 will where down my syncros. I looked at a few stores today and anything in that weight was either gl5 only or gl4 and gl5 both. Would the one that covers both be ok for the trans? I am going to stop at a few other places tomorrow and check for gl4 only again but was wondering just in case I cant find anything

 

[MrGiggles]

My owners manual states 75W-90 GL4 or GL5 for any temp, and 80W-90 GL4/5 for 50*F and up.

I used Supertech 75W-90 semi-synthetic last time, just because it's only 5 bucks a quart and relatively easy to find. I see a lot of posts recommending Redline MT90 or Royal Purple, but those aren't available locally without paying out the nose.

My transmission shifts fine with the ST fluid.

 

[kms1990]

i put castrol synthetic 75w90 in mine and it works just fine

 

[pcb]

If you have trouble shifting in the cold weather, you can go with synchro-mesh oil.

(I made my own,... ATF Type-F + 1 Liter Lucas Oil,... I love it,... I used to grind every gear for 15 min. in the cold. It always shifts now,... It's been in for two years now with no problems. (but I don't slam gears). (ATF Type-F was recommended for my 1983 Mazda GLC for cold weather))