Mercury Mariner Service Manual 6, 8, 9.9 210CC Sailpower, Page 107Get this manual
19Remove (and discard) seals (a) 4Replace forward gear bushing if area on propeller shaft that bushing contacts is pitted or worn or if bushing is worn or pitted Press bushing from gear using Mandrel (a) (91-13656)
PINION GEAR and FORWARD GEAR
1After drive shaft is removed, reach into gear housing and remove pinion gear (a), thrust washer (b), and forward gear (c) 2Replace pinion gear if it is chipped or worn 3Replace forward gear if gear teeth or clutch teeth are chipped or wornIMPORTANT: If bearing or race requires replacement, replace bearing and race as set