Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 247Get this manual
Forward Gear Bearing Cup INSTALLATION Fo rward Gea Backlas.017 into .028 in (O.43mm to O.71mm)
Press the bearing cup into the gear housing using the installation tool as follows:
Note: If the forward gear, forward gear bearing and cup, or gear housing were not replaced, install the same quantity of shims that were taken out when cu was removedIf the forward gear, forward gear bearingcup, or gear housing were replaced, install 0.020 in (0.51mm) of shimsNote; If backlash has already been checked and it has determined that it needs to be adjusted, (see Checking Forward Gear Backlash), adding or su btracting .001 in(O.025mm) shims will change the gear backlash by the sam amountExample (if backlash is too high)
IMPORTANT: Verify that the bearing cup is position as straight as possible to avoid cocking it in the bore while pressing it in
If Forward Backlash Checks:
Middle of Specification: