Mercury Mariner 4 and 5HP 4-Stroke Outboards Service Shop Manual 1999, Page 218Get this manual
SHIFT LINKAGE
3Install starter lock rod (a)and secure with snap (b)
4Install upper shift shaft assembly (a) into drive shaft housing5Secure lever (b) on shaft (c) of shift lever with screw (d) as shownTighten screw securely