1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 198Get this manual
7Lightly turn drive shaft back-and-forth (no movement should be noticed at propeller shaft)8Dial Indicator registers amount of backlash, which must be between specification shown in chartDIAL INDICATOR MINIMUM 0.012 in(0.30mm) 0.015 in(0.38mm) READING MAXIMUM 0.019 in(.48mm) 0.022 in(0.55mm)
3Lubricate o-ring (c) and areas (d) with 2-4-C w Teflon (92-825407A12)4Install bearing carrier and propeller shaft into housing with the word "TOP" located on flange (e) toward top of housing
MODEL 75-thru-90 (3 Cylinder) 100115125 (4 Cylinder)
9If backlash is less than the minimum specification, remove shim(s) from in front of forward gear bearing race to obtain correct backlashWhen reinstalling pinion nut, apply Loctite 271 on threads of nut10If backlash is more than the maximum specification, add shim(s) in front of forward gear bearing race to obtain correct backlashWhen reinstalling pinion nut, apply Loctite 271 on threads of nut By adding or subtracting 0.001I (0.025mm) shim, the backlash will change approximately 0.001I (.025mm)