I just changed my CV axles and seal and changed transmission fluid. My car never grinded before changing fluid. I used 2.7 quarts of redline mt-90... Any suggestions? It didn't grind at all last night but today on my way to work 3rd gear grinded hardcore... I was thinking of using 1 quart Pennzoil mesh and 1.7 quarts of redline does that sound like a good idea? It doesn't grind at high rmps tho just lower rpms. I can shift above 4k with no issues but below its cruuussss sound haha.

http://www.6gc.net/forums/index.php?showtopic=93280

I had a very similar problem. Apparently it's pretty common. Not saying it would necessarily fix your problem but I went full synchromesh, fixed it right up.

+1 on full pennzoil synchromesh. I can tell you that cured the majority of everyone's S series grind problems.