2001 Mercury Mariner 50-60HP Factory Service Manual, Page 444Get this manual
NON-BIGFOOT GEAR HOUSING
Determining Forward Gear Backlash
NOTE: Read entire procedure before attempting any change in shim thickness1Obtain correct pinion gear location; refer to "Determining Pinion Gear Location", preceding2Install Bearing Preload Tool on driveshaft; refer to "Determining Pinion Gear Location", preceding3Install components as shown4While holding the driveshaft, torque the puller bolt to 45in-lb5Rotate driveshaft 5-10 revolutionsThis should properly seat the forward gear tapered roller bearingRepeat step 4