Mercury Mariner 4 and 5HP 4-Stroke Outboards Service Shop Manual 1999, Page 202Get this manual
GEAR HOUSING
IMPORTANT: Make sure taper of cam is opposite to bend in shift shaft as shown5Secure cam (a) to shitt shatt with roll pin (b) and install (center) pin (c) in shatto
6Lubricate O-ring (d) with 2-4-C wffeflon Marine Lubricant and install into water pump base