DRAGUL

Tried doing a search but revealed no answers. Took the car out tonight and had a issue where the transmission started grinding on second and third. It is the Tremec 3650. It will go into gear fine with no grinding, but when the clutch is released is when it grinds. It is a quick loud grind, then it is fine with no noise or issues. Now I did have the rear tail shaft bushing replaced 3 months ago due to, the bushing being worn and causing the rear seal to leak. Also replaced the throwout and pilot bearing. They replaced the oil using Redline. I am wondering if the oil is causing synchro problems? I didn't have any problems before this, except the leak. Any help would be appreciated. Also car has the spec stage 3 clutch (previous owner) and stock cable setup.