I have a '98 GSR and it grinds going into 3rd gear. I hear that the 3rd gear is usually the first to go on a GSR, but I can be very wrong. Is there some things that I should do before I replace the syncro or the whole tranny?, such as replacing the tranny fluid?

 

Synchro's are relatively cheap. Just messing with the fluids will only delay having to replace them. Labor will bite you in the *** though.