Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 254Get this manual
15If clearance between shimming 1001 (c) and pinion gear (d) is .025 in(0.64mm)pinion gear depth is correctInstall the bearing carrier retainer nut (lightly lubricated) into the gearcase until full thread engagement is obtainedInslall the two jaw bearing puller with the jaws holding on the retainer nut and the boll pressing against the propshaftTorque the boll to 50 lbin(5.6 Nm)This propshaft preload seats the reverse gear and minimizes reverse gear movement while measuring backlash Rotate the drive shaft clockwise 10 complete revolutions to seat Ihe drive shaft and reverse gear bearingsInslall the Backlash Indicator Tool (91-53459) and Dial Indicator (9 1-58222A 1)The indicator rod should be perpendicular to MARK on the indicator tool ann56 aFeeler GaugeLocating ToolShimming ToolPinion Gear
16If clearance between shimming tool and pinion gear is above or below .025 in(O.64mm)reshim drive shaft tapered bearing race to raise or lower pinion gear, as follows: abcRemove pinion gear retainer nut and collarRemove drive shaftRemove or add an amount of shim(s) under upper tapered bearing race sufficient to correct pinion gear depthEXAMPLE: Pinion gear depth is 020in(0.51mm) Add 005in(0.13mm) Pinion gear depth will be 025 in (O.B4mm) Pinion gear depth is 030in(0.76mm) Subtract .005in (0.13mm) Pinion gear depth will be 025 in (O.Slmm) Shaft and Pinion preceding