300 posts and you still don't know where the newb manuals are? http://www.mnsubaru.com/forums/showthread.php?t=18486 Just did it yesterday, it's liquid sex for your transmission.
Did this for the 92x about a week ago. Definately feels smoother and easier to get into gear. The real test will be this winter when things get cold. It was very easy to do and well worth it.
I think another real test is after you've had it in for 6-7K miles... After I had my clutch done, I put straight redline (the one they recommend for our MT) worked great for about 6-7K, now I'm getting a grind going into 5th more than 90% of the time.
If you want something simpler, try straight Amsoil Severe Gear 75w-90(also 75w-110 and 75w-140 available). I've been running it in my Forester for 2 years now, beautiful stuff, very usable during the colder months, and it doesn't get worse as time goes on. 2 years later, and it's as good as the day I put it in. I've never ground a gear once that wasn't from user(brain-foot/hand) error. Since we do run in pretty cold temps, it is nice to run a non-dino fluid that doesn't turn to jelly on those cold, cold days and Amsoil has the lowest pour point I'm aware of for any tranny oil, -60C, a good 30 degrees lower than a comparable dino like Castrol's Hypoy-C.
