2001 Mercury Mariner 50-60HP Factory Service Manual, Page 503Get this manual
BIGFOOT GEAR HOUSING
6Assemble Pinion Gear Locating Tool (91-12349A2) as shown; do not tighten collar retaining bolt at this time
a -Arbor -Gauging Block; Install With Numbers Away From Split Collar -Bolt; Gauging Block Retaining
d -Split Collar -Bolt; Collar Retaining -Snap Ring
7Insert tool into forward gear assembly; position gauging block under pinion gear as shown
a -Gauging Block 8Remove tool, taking care not to change gauging block position, and tighten collar retaining bolt9Insert tool into forward gear assembly; position proper numbered flat (from chart) of gauging block under pinion gearMODEL GEAR RATIO (PINION GEAR TEETHREVERSE GEAR TEETH) USE FLAT NOLOCATING DISC NO