Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 246Get this manual
Gear Housing Reassembly Gear Housing Inspection
1Clean the gear housing thoroughly with suitable solvent and hard bristle brushDry the gear housing thoroughly using compressed airInsure that all sealants, tocking agents and debris are removedVerify the oil circulation holes in the drive shaft bore are clear and free of debrisInspect the gear housing for excessive corrosion, impact or any other damageExcessive damage andor corrosion requires replacement of the gear housing Inspect the bearing carrier retainer threads in the gear housing for corrosion andor stripped threadsDamage or corrosion to the threads requires replacement of the gear housingInspect bearing racecup contact areas for evidence of bearing cup spinning Check that bearing cups are not loose in bearing boresAnyone bearing bore in which the racecup is loose will require replacement of the gear housing Inspect for blockage in water inlet holes and the speedometer ho le, clean as necessaryBe careful not to enlarge the speedometer hole as this cou ld cause erroneous speedometer readingsMake sure that the locating pins are in place in the gear housing and that the corresponding holes in the drive shaft housing are not elongatedThe drive shaft may break if the housings are not aligned properly due to missing locating pins or elongated holesInsert the driver with the bearing assembly, into position (by way of the propeller shaft bore) at the drive shaft bore as shown