Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 196Get this manual
8Replace FORWARD gear race if it is rusted or damaged or if FORWARD gear tapered bearing must be replacedRemove race from housing using Bearing Puller Assembly (91-83165M) and Puller Plate (91-29310) Drive Shaft Bushing, Bearing and Lubrication Sleeve
1Inspect drive shaft bushing and bearing surface to determine condition of corresponding upper drive shaft bushing and lower drive shaft needle bearingIf drive shaft surface is rusted, pitted, discolored (blued lack of lubrication) or worn; replace drive shaft and corresponding bushing bearingDO NOT remove bushing or bearing if replacement is not necessary