2001 Mercury Mariner 50-60HP Factory Service Manual, Page 477Get this manual
BIGFOOT GEAR HOUSING
Pinion Gear, Drive Shaft, and Forward Gear
1Hold drive shaft using Drive Shaft Holding Tool; remove (and discard) pinion nutModel 4050 Bigfoot (4-Stroke) 5060 Bigfoot (4-Stroke) 7590 (4-Stroke) 60 Bigfoot (2-Stroke) 7590100115125 (2-Stroke) Drive Shaft Holding Tool 91-56775 91-817070A1 91-804776A1 91-56775 91-56775
2Remove drive shaft, pinion gear, pinion bearing and forward gear3Replace pinion gear if it is chipped or worn4Replace pinion bearing and race if either are rusted, pitted or damaged; or if bearing does not roll freelyTo remove race, refer to "Lower Drive Shaft Bearing Race," following5Replace forward gear if gear teeth or clutch teeth are chipped or worn