Originally Posted by iminhell
Yes the grind/lockout is a trans issue.
The syncro's can't match speed fast enough at high RPM. Using a lower viscosity fluid helps.
I run 5w-30 motor oil and shift without issue @8,000RPM.
The thinner fluid allows the syncro's to catch up faster, less resistance.
You use motor oil in your transmission? Color me confused... But I don't remember it having this issue before I asked my dealer to switch out the transmission fluid...
As for OP, did this answer any questions?