Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 266Get this manual
13Rotate drive shaft to verify PINION GEAR and FORWARD GEAR are meshing properly and propeller shaftlbearing carrier assembly are full seated in gear housingIMPORTANT: Prior to installation of shift shaft, verity that the round retaining ring andE" ring are in position and secure14Apply light coat of Perfect Seal (92-34227- 1) to the threads of the shift shaft bushing15Insert shift shaft down shift shaft hole in gear housing and into shift camIt may be necessary to rotate shift shaft back-and-forth slightly in order for splines of shift shaft to match up with splines of shift cam 16Thread bushing into positionUsing Shift Shaft Bushing Tool (91-311 07), torque shift shaft bushing to 50 lbft(67.8 Nm)