1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 197Get this manual
DETERMINING FORWARD GEAR BACKLASH
5Install components as shown
NOTE: Read entire procedure before attempting any change in shim thickness1Obtain correct pinion gear depth; refer to "Determining Pinion Gear Depth," preceding2Install Bearing Preload Tool (91-14311A1) on drive shaft; refer to "Determining Pinion Gear Depth," preceding3Install components as showna Propeller Shaft Bearing Carrier (Assembled) Puller Jaws (91-46086A1) Puller Bolt (91-85716); Torque to 45 lbsin(5.1 Nm)
Refer to "Bearing Carrier and Propeller Shaft Installation," following