Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 301Get this manual
3 Measure distance (a) and increase that distance by in (2S.4mm) by turning bottom nut away from top nut
Pinion Gear Location
CHECKING Pin ion Gear Locati on Sp ecif ication.025 inlO.64 mm) NOTE: If the bearing preload tool has not already been set up see Orive Shaft Bearing Preload Toor, 'Installation' section found on page 6B-38 firstPlace the pinion gear shimming tool into the gear housing
NOTE: Take the following measurements at locations, rotating the drive shaft 120 degrees between each reading (always rotate the rive shaft in clockwise direction) 2Insert the thickest feeler gauge that fits snugly between one tooth of the pinion gear and high point of the shimming tool
aMeasure dislance and Increase by in(25.4mm) b_-Bottom Nut (screwed down by approximately in(25.4mml]