If I remember correctly, the Mobil 1 fluid is GL-5 rated. The brass syncros in our trannies don't like GL-5 fluid. Eric Waterman 1996 200SX SE-R 1997 200SX SE-R 1991 Sentra SE-R > Jason Gould wrote: > Okay, I did my gear oil and used Mobil 1 Synthetic Gear Oil - which is what > you use in a manual.