I have a 2003 Evo 8. I was in 5th gear going 70mph. I started hearing a chattering or knocking noise. I pull over and try to put the car in neutral as I am coasting to a stop to check it out. It was really hard to get it out of gear, I finally got it in neutral and it stalled and made a clunking noise when I let out the clutch (In neutral??!). It could barely shift thru the gears when the car was off. It felt stuck. I could start it when I had the clutch in, but as soon as i let it out it would stall. The car had NO issues before this. Tranny was smooth. No noises. This was really random. Is my tranny done?? Any ideas what happened? Please let me know.
Thanks,
Nikki

 

Pop the transmission housing plug and shine a flashlight in through the top, see if you can see anything.

Sounds like a clutch/top issue.