Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 310Get this manual
IMPORTANT: Be careful when inserting the propeller shaft assembly into the gear housing as the needle bearings in the reverse gear bearing adaptor can become dislodged If it is suspected that needle has become dislodged, remove the propeller shaft assembly and inspect the needle bearing cages for damageIf the cages have not been damaged and needle bearing is mispositioned, it can be snapped back into place3To allow for the engagement of the shift spool with the shift crank, tilt the propeller end of the propeller shaft assembly to the left (port) side of gear housing and begin to lower it into the gear housing 4With the propeller shaft assembly tilted to the port side of the gear housing, continue to lower the assembly until the reverse gear hub comes into contact with the reverse gear bearing adaptor and the propeller shaft is fully inserted into the reverse gear