[BrandonWRX]

I have 5 quarts of redline D4 ATF synthetic (rated at gl-4) left over from my 4eat 04 wrx. When checking my sti tranny fluid level, it is halfway between L and H. Im thinking this might be the cause of some subtle grinding here and there and some 1-2 shift problems at redline. For example when im at the strip, the 1-2 shift takes wayyy too long and it is as if I hit a barrier between the 1-2 shift before the synchros work and it goes in, still with some difficulty. When the car is cold I have to double clutch just to downshift into 2nd at a low speed. This is in 90 degree weather, god knows how itll be once it starts getting cold.
So my question is, could I add some gl4 redline synthetic atf to the stock oil to fill it up? Other gl4 rated tranny fluids such as redline shockproof and gm synchromesh are used in the tranny without problems. I would only add 0.5 qts at the most. What do you think?

PS-I know hypoid gears in the front diff require gl5, just trying to get the synchros to work better.

[Xman]

wait, you put ATF in your 6MT?? :O


Please please please do not do that. ATF is way too thin for a manual transmission and will probably make your shifting even worse becuase it tends to be slipperier which will further reduce the effectiveness of your synchros.

Down half a quart should not make a big difference. Check the multiple trans oil threads for research and change over to what you think is going to be best for you.

[BrandonWRX]

Originally Posted by Xman

wait, you put ATF in your 6MT?? :O


Please please please do not do that. ATF is way too thin for a manual transmission and will probably make your shifting even worse becuase it tends to be slipperier which will further reduce the effectiveness of your synchros.

Down half a quart should not make a big difference. Check the multiple trans oil threads for research and change over to what you think is going to be best for you.

haha no I didnt put any in, I figured it was too thin. The only thing is, other gear oils that people use such as synchromesh and shockproof lightweight are gl4 also...too thin, but they work well when mixed with dino oil. This is also temporary, since Ill replace with "Uncle Scottys c ocktail" in around 5000 miles or so. I get a small amount of grinding, which I figured to be that .5 qts that it is missing sinc ethe fluid gets hot and thin and makes the synchros not work as well. *It is a 70W80 as opposed to a 75W90*

[BrandonWRX]

no other feedback?

[Pitcherman]

DO IT!!! It's not my trany, be a guinie pig, and let us know.

Chris