Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 453Get this manual
CHECKING FORWARD GEAR BACKLASH NON-RATCHETING
1Install the appropriate spacer shim into the gear housing
3Insert Forward Gear Installation Tool (91-815850) into forward gearbearing adaptor assembly
55428ShimForward Gear Installation Tool (91-815850)Forward GearSearing Adaptor Assembly
2Apply Quicksilver Super Duty Gear Lubricant to thrust bearing and install thrust bearing and thrust race onto forward gear bearing adaptor