Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 443Get this manual
Drive Shaft and Pinion Gear INSTALLATION (FOR CHECKING GEAR LOCATION AND BACKLASHES ONLY)
NOTE: If the original shims were not retained or if pinion gear, drive shaft, drive shaft tapered roller bearing and cup, or gear housing were replaced, start off by installing 0.038 in(0.96 mm) shim(s)NOTE: If the original shims were retained (or measurement known) and none of the above listed parts were replaced, reinstall the original shims (or an amount of shims equal to the original shims)
4Insert the drive shaft into the gear housing drive shaft boreIt may be necessary to rotate the drive shaft to engage the drive shaft splines into the pinion gear splines5Temporarily install the propeller shaft (without the sliding clutch installed) into reverse gear6Insert the pinion nut adaptor (with the nut) into the gear housingIt may be necessary to raise the drive shaft slightly to clear the tool7Start the pinion nut onto the drive shaft threads by rotating the drive shaft until the nut is snug