Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 456Get this manual
5If backlash is MORE than the specified MAXIMUM, REMOVE shim(s) from in front of forward gear bearing race to obtain correct backlashWhen reinstalling pinion nut, apply Loctite 271 to threads of nut6If backlash is LESS than the specified MINIMUM, add shim(s) in front of forward gear bearing race to obtain correct backlashWhen reinstalling pinion nut, apply Loctite 271 to threads of nut aRemove the bearing carrier retainer, tab washer, and the bearing carrierbcUsing the hook tool remove the forward gear bearing adaptorInsert the forward gear installation tool into the forward gear and remove the forward gear, thrust bearing and thrust race
dRemove the propeller shafteRemove the spacer shimf"Drive ShaftBearing Preload Tool", 'Removai' section