Transmission going soon?
 

I am reaching the 100k mark on my car, and my manual transmission is acting up. Just wondering if these signs mean im gonna need a new transmission soon....also wondering if there is a 6 speed available if this one goes.
-when in nuetral off the clutch the transmission makes a metal on metal grinding noise
-real nothchy shifting
-can barely get into 1st and reverse
-really loud clicking when I shift

well any info would help...really just need to know if these signs are severe, and if im gonna be purchasing a new transmission in the next month.

~Chris~
300ZX N/A 2+2