car just started making a grinding sound when shifting in third gear just got the swap last month..... question is how long can you drive until third gear goes....

 

Get yourself some Pennzoil Synchromesh, change the fluid. Stuff works great. It's not a fix, but it will get you through until you are ready to replace the synchros. Definitely worth the money. PS it takes a few days of driving to penetrate into the synchros, so be patient.