Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 252Get this manual
Pinion Gear Location CHECKING AND ADJUSTING
Pinion Depth.025 in(O.64mm)
Note: If the bearing preload tool has not already been set up see "Drive ShaftBearing Preload Tool", 'Installation' section found on page SA-35 firstPlace the pinion gear shimming tool into the gear housing
Note: Take the following measurements at 'aeaticns, rotating the drive shaft 120 degrees between each reading (always rotate the drive shaft in clockwise direction)
If the average pinion gear height is not correct, remove the bearing preload tool, the drive shaft retainer and the dri ve shaft tapered roller bearing cup(The cup can be removed by wiggling the dri ve shaft back and forth or by turning gear housing and shaking it Add or subtract shims beneath the cup to obtain the proper average pinion gear heightReinstall the cup and retainerRetorque retainer to 100 lbft(135.5 Nm) Reinstall the bearing preload tool and rotate the drive shaft at least full turns in clockwise direction Recheck the pinion gear height as in step aboveRepeat this process until the average pinion gear height is within specificationInsert the thickest feeler gauge that fils snugly between one tooth of the pinion gear and high point of the