The fluid that's in there (Mobil 1 ATF, i belive) is red automatic transmission fluid. Syncromesh is more the color and consistancy of motor oil, although noticibly sliperier (did I just make up a word?). Any mechanic will notice the difference. I can't say weather or not it will cause a warranty issue though. I would think not, unless there is a problem and the dealer can link the failure directly to the fluid.