I have a Penn slammer 3 6500 that is grinding when retrieving. I changed the main and pinion gear and thought the problem was done.When I turned the rotor everything was like new. However ,when I put the handle on and turned the handle the reel sounded like a coffee grinder. There is only 1 shim on the main gear. I put the handle on the other side and the same problem occured. Could it be the side plate bearings that are causing the problem?
It would be worth cleaning them out , once you pull them out you might feel it rite away .
Turns out the gears weren`t meshing properly.Added more shims to rectify the problem.