2001 Mercury Mariner 50-60HP Factory Service Manual, Page 506Get this manual
BIGFOOT GEAR HOUSING
6Install components as showna -Threaded Rod (Obtain Locally) -Washers -Nuts -Dial Indicator Adaptor Kit (91-83155) -Dial Indicator (91-58222A1) -Backlash Indicator Tool
7Position Dial Indicator on appropriate line (from chart below) marked on Backlash Indicator ToolMake sure the dial indicator is perpendicular () to the indicator tool or an inaccurate reading will be obtainedBACKLASH INDICATOR TOOL 91-78473 91-78473 91-196601 91-78473 91-78473 91-196601 ALIGN POINTER OF DIAL INDICATOR WITH MARK 1