1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 309Get this manual
BIG FOOT
Cleaning and Inspection
Gear HousingBearing Carrier Castings
1Thoroughly clean gear housingbearing carrier castingsBe sure all old gasket material is removed from mating surfaces and that carbon deposits have been removed from exhaust passages2Inspect castings for cracks or fractures3Check sealing surfaces for nicks, deep grooves and distortion which could cause leaks4Check water passages for obstructions
Ball Bearings
CAUTION
DO NOT spin-dry ball bearings with compressed air1Clean bearing in solvent and dry with compressed air2Bearing should be free of rust stains3Attempt to work inner bearing race in-and-outThere should not be excessive play4Lubricate ball bearing with Quicksilver Gear LubeRotate inner bearing raceBearing should have smooth actionIf ball bearing sounds or feels rough or has catches, remove and discard bearingRefer to "Bearing Carrier" following