Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 462Get this manual
Bearing Carrier Assembly Final Installation (Ratcheting)
1Install the appropriate spacer shim into the gear housing
3Place the thrust hub on top of the thrust bearing with the wide flat side against the thrust bearing
50785Thrust HubWide Flat Side
4Use the Forward Gear Installation Tool (91-815850) to install the forward gear down over the propeller shaftEnsure that the thrust hub seats evenly onto the shimTap the race down lightly using soft punchDo not damage the thrust race surface50782Shim