2003+ Suzuki DF9.9/DF15 four stroke outboard motors service manual, Page 186Get this manual
LOWER UNIT 8-21
LOWER UNIT GEARS- SHIMMING AND ADJUSTMENT
If the lower unit has been rebuilt or has had components replaced, shimming for correct gear contact and backlash will have to be adjusted to ensure smooth, reliable operation of gearsShimWasherMounting position Numerical indexitem Pinion gear back up shim Forward gear back up shim Forward gear thrust washer Available thickness (mm) 0.7, 0.8, 1.1, 1.2, 0.7, 0.8, 1.1, 1.2, 1.5 1.3, 1.4, 1.7, 1.8, 0.9, 1.0, 1.3 0.9, 1.0, 1.3 0.9, 1.0, 1.3 Design specification thickness (mm) 1.0 1.0 1.5 1.5 1.0