buddy needs help
 

My buddy has an 02 v6 stang that he recently got and also recently replaced the clutch on, but as of today it started grinding gears out of nowhere, not sure what it could be its grinding as he puts it into the gears sometimes all of them sometimes just one or 2, but i told him it could be the throwout bearing but unlikely cuz he says it was replaced, could it be something simple like low tranny fluid for some reason? some1 told me it could be a syncronization issue but i dont know how to fix that... so any advice or opinions?

If its a new clutch, it may not have been installed correctly. It could also be low fluid levels. Check the fluid level first, then if that's not right check the clutch cable at the fork, and shine a light inside the inspection cover and try to see if the new clutch looks alright.

It may just also be clutch chatter as the new clutch is breaking in (i.e., is he sure it's grinding?).

If the synchros are shot, the only option is to replace them, which means you may as well just rebuild the tranny while its off the car. It would be strange for synchros to go from good to worn, but if the fluid wasn't properly replaced/refilled after the clutch was put back on I could see that happening.

It could be a lot of things. I always start with the easy stuff like making sure the clutch is adjusted correctly to fully engage and disengage the clutch when the pedal is pressed as this can cause that problem.