sounds like your throw out bearing is going out
Probably could make your own thread... but my guess would be a loss of hydraulic pressure.Hey! your truck sounds like what mine just started doing almost. some history....'04 NV5600, 325hp 4x4 quad cab, 192,000 mi.
So, while I was in Indiana this past week, clutch acted just like it didn't release...had to shut it off to put it into 1st gear then I shifted it like a big rig to finish a short distance. ...later it would shift but could tell it was taking excessive syncro pressure to do it and after that a time or two while trying to put it into gear I got the squeal mentioned...like thin metal scraping???
But other times everything works just like when it was new. Any idea's?