4 Spd slight grinding when shifting.

put a few more miles on it with the new oil.
wouldnt hurt since you made up your mind to swap it any how.

maybe your title shouldnt have been "slight grind" haha sounds worse than originally stated, my grind was pretty bad and there was also some metal flakes ...

yeah check you oil pressure and check that release fork. like ^^^^^^^^ he said. . . make sure you burp out air if you have hydraulic.