Mercury Mariner Outboards 2.2 / 2.5 / 3.0 Service Shop Manual, Page 65Get this manual
Gear Backlash Check
Assembling Water Pump Housing
9Install new seal (a) into housing using suitable mandrel (or socket) and driver rod
8Pull up on drive shaft and hold so that it will not rotateWhile pushing in on propeller shaft, rotate propeller shaft back and forthThere should be play between the gears (a clicking sound should be heard as the shaft is rotated back and forth) NOTE: The amount of play between the gears is not criticalbut no play between the gears is unacceptableIf there is no play between the gears, check that bearings are completely seated in housing If bearings are seated properly, remove shim(s) until play is obtained between gears'Shim Kit (15-95292) contains shims (.002 in, .004 inand .008 in [.05mm.10mm and .20mm]