Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 435Get this manual
LEFT HAND NON-RATCHETING
Reverse Gear Bearing Adaptor Assembly
INSTALLATION
NOTE: If the reverse gear, reverse gear adaptor, large thrust bearing, or bearing race in the gear housing were not replaced, install the same shim(s) (or the same thickness of shim(s)) that were taken out when adaptor was removedIf the reverse gear, reverse gear adaptor, large thrust bearing, bearing race, or gear housing were replaced, install 0.008 in(0.51 mm) of shimsNOTE: If backlash has already been checked and it has determined that it needs to be adjusted, (see Checking Reverse Gear Backlash), adding 0.001 in(0.025 mm) shims will reduce the gear backlash by approximately 0.001 in(0.025 mm)Subtracting 0.001 in(0.025 mm) shims will increase backlash by approximately the same amountExample (if backlash is too high) Backlash checks: (subtract) middle of specification: You get: add this quantity of shims: Example (if backlash is too low) middle of specification: Backlash checks: (subtract) You get: subtract this quantity of shims: 0.025 in0.009 in0.016 in(0.64 mm) (0.23 mm) (0.41 mm) 0.045 in0.025 in0.020 in(1.14 mm) (0.64 mm) (0.51 mm)