Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 251Get this manual
4 With tapered end of upper roller bearing facing up (to wards crankshaft splines), slide tapered bearing over crankshaft end of drive shaftSlide bearing installation tool (91 12364) over crank shaft end of drive shaftIMPORTANT: Prior to installation 01 drive shaft, re move any grease oroil from tapered area of drive shall pinion gear splinesThis will provide uniform seat fOI the pinion gear resulting in more accurate pinion depth measurements9Inslall the drive shaft assembly with races into the geal housing10Make an alignment marl with crayon (if nol done pre viously during disassembly) approximately in(10 1.6mm) above water pump keyway on drive shaftMake corresponding marl on pinion gearWith drive shaft and pinion gear marks alignedposi lion marks on pinion and drive shaft in line with fixed reference painton gear case Edowel pin, boll holeetcWith pinion gear meshing with reverse gear, secure pinion gear to drive shaft with flat washer and nut
6Thread used pinion nut onto drive shaftDO NOT allow drive shaft pinion threads to extend beyond pinion nut7Using press against the pinion nut, seat upper ta pered bearing on drive shaft