I've never experienced any grinding issues going into any gears prior to finding a leak in my clutch hose last week. I have an 05 6MT coupe with (i believe) a C009 tranny with approx 130k miles.

I had the car towed to my mechanic (seeing i could not get the car in gear since the pedal was completely depressed). After replacing the stainless steel hose....for whatever reason, third gear now grinds horrendously. Hes checked all the fluids and everything appears to be full. He said he bled the clutch line as well.

Neither him or myself have any idea why the car would be doing this. He believes it may be a synchros issue, however i have never experienced any grinding issues before. Not even in the slightest bit. At a complete standstill, i cant even get the car into third! It feels like I'm playing the game "Operation" and BUZZES every time i try to place it in 3rd WITH the clutch disengaged. When driving it will go into third but grinds loudly every time. Is there something that could have gone wrong swapping the hose? Could something have gotten misaligned? I have had the car for awhile and know it's feels in and out. I could be wrong, but i feel like if it was a synchos issue, i may have noticed something even faintly, before the clutch line went bad.

Anyone have any idea what this could be?

 

you could have a broken pivot ball. same thing just happened to my brothers 350z
also it sounds like you arent fully extending your slave cylinder. thats either due to a worn seal or cylinder or air in the system still.