So here is my problem. I own a 2003 DE my transmission recently started grinding in 3rd and 5th gear. So I read this forum and did what most users did, which is swap it out for a 009. I found one at a local junkyard from a 05 g35 with 60k miles. I replaced all the hardware before installing(pivot ball, fork, shifter bracket, and slave and jwt clutch and flywheel with TO bearing) because I didn't want this unit to have any issues. The shifter linkage was ripped off the 009 so I was able to knock the pin out and put the linkage from the original tranny on there.

Well we dropped the transmission and put everything back in. I test drove it and no grinding. It was smooth as butter until I got on the interstate. When I was in 5th gear and took my foot off the accelerator the gear popped completely out. When the accelerator was pressed it stayed in gear but every time you take it off the pedal it popped out. This only happens in 5th gear. Is the transmission toast? I am pretty pissed but that won't help the situation. Any ideas?

 

Try adjusting the position of the shifter. Most of the shirt-shift kits provide instructions, and it just takes a minute. Did it on mine years ago, but can't recall the procedure.