Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 388Get this manual
RIGHT HAND NON-RATCHETING
5Measure distance (a) and increase that distance by in(25.4 mm) by turning bottom nut away from top nut1 in(25.4 mm)
aDistanceAdaptorLedge 6Turn driveshaft clockwise or more turns to seat driveshaft bearings7Insert Pinion Gear Locating Tool (91-74776) into gear housing until it bottoms out on bearing carrier shoulderPinion Gear Locating Tool (91-12349A2) can be usedUse flat #7 and disc #2Follow instructions supplied with tool8Determine pinion gear depth by inserting feeler gauge thru access slot in pinion gear shimming tool9Clearance between shimming tool and pinion gear should be 0.025 in(0.64 mm)10If clearance is correct, leave Bearing Preload Tool on driveshaft for "Determining Forward Gear Backlash," following11If clearance is not correct, add (or subtract) shims at location shown to raise (or lower) pinion gearWhen reinstalling pinion nut, apply Loctite 271 on threads of nut and retorque pinion nut