1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 215Get this manual
General Service Recommendations There may be more than one way to "disassemble" or "reassemble" particular part(s), therefore, it is recommended that the entire procedure be read prior to repairIMPORTANT: Read the following before attempting any repairsIn many cases, disassembly of sub-assembly may not be necessary until cleaning and inspection reveals that disassembly is required for replacement of one or more componentsService procedure order in this section is normal disassembly-reassembly sequenceThreaded parts are right hand (RH), unless otherwise indicatedWhen holding, pressing or driving is required, use soft metal vise jaw protectors or wood for protection of partsUse suitable mandrel (one that will contact only the bearing race) when pressing or driving bearingsWhenever compressed air is used to dry part, verify that no water is present in air line
Inspect all bearings for roughness, catches and bearing race side wearWork inner bearing race in-andout, while holding outer race, to check for side wearWhen inspecting tapered bearings, determine condition of rollers and inner bearing race by inspecting bearing cup for pitting, scoring, grooves, uneven wear, imbedded particles andor discoloration from over-heatingAlways replace tapered bearing and race as setInspect gear housing for bearing races that have spun in their respective boresIf race(s) have spun, gear housing must be replacedRoller bearing condition is determined by inspecting the surface of the shaft that the roller bearing supportsCheck shaft surface for pitting scoringgrooving, imbedded particles, uneven wear andor discoloration from overheatingThe shaft and bearing must be replaced if such condition exists