2001 Mercury Mariner 50-60HP Factory Service Manual, Page 442Get this manual
NON-BIGFOOT GEAR HOUSING
3Measure distance between top of nut and bottom of bolt head4Increase distance by in(25.4mm)5Rotate driveshaft 10 revolutionsThis properly seats upper driveshaft tapered roller bearing
aDistance, in(25.4 mm)NutBolt 6Insert Pinion Location ToolPosition access hole as shownInsert feeler gauge between gauging surface and pinion gear