Ok, so today while I was driving on the highway I downshifted to 4th to pass a car and got to about 5k rpm before shifting to 5th, but when I went to shift it wouldn't go into gear. I tried pushing it up into gear and it made a grinding sound and I tried just easing it in and it wouldn't go. So then I tried putting back in 4th (all this time going about 80 and holding the clutch) but it wouldn't do that either, so i slowed into the break down lane and when I got down to about 30-ish tried putting in in 2nd and it worked. After that I kept going, shifted good until 5th and I had to sorta force it to go into place. After that it worked fine, shifted easy in all gears, but it worries me. Is it a tranny problem? or clutch? or anything else?
Also it's always had a bit of a problem shifting into 2nd gear, it doesn't grind or anything, it just doesn't shift smoothly. And about 2 months ago I had the tranny and clutch replaced. It had the 2nd gear problem before and after.

 

The clutch might have spun and got hot. This happened to me once before at the drag strip. After I let the cluch cool it was fine..