1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 188Get this manual
Forward Gear Bearing Race IMPORTANT: Retain shim(s) for reassembly1Remove race and shim(s) Hammer (91-34569A1)using Slide
Reassembly
Forward Gear Bearing Race
1Place shim(s) (retained from disassembly) into housingIf shim(s) were lost, or new gear housing is being assembled, start with 0.010I (0.254mm) shim(s)2Assemble components as shown; drive race into housing by striking propeller shaft end with lead hammer
aRaceShim(s)Slide Hammer (91-34569A1)
Trim Tab Adjustment and Replacement
IMPORTANT: The trim tab is made of special alloy to aid in protecting the drive shaft housing and gear housing from galvanic corrosion (corrosion and pitting of metal surfaces)Do not paint or place protective coating on the trim tab, or trim tab corrosion protection function will be lost1Replace trim tab if 50 (or more) consumedMark location of old trim tab on anti-ventilation plate before removal; install new trim tab in same location2The trim tab provides means to offset (balance) some of the "steering load" that is caused by "propeller torque" at higher operating speedsIf at higher speeds the boat turns more easily to the left, loosen bolt, move the trim tab (trailing edge) to the left (when viewed from behind); retighten boltTurn trim tab (trailing edge) to the right if the boat turns more easily to the rightaShim(s)Race, Apply Quicksilver Needle Bearing Assembly Lubricant on O.DcMandrel (91-31106)