1985 Mercury Outboard V-300 V-3.4L Shop Service Manual, Page 190Get this manual
Installing Gear Housing to Drive Shaft Housing AWARNING
Disconnect high tension leads from spark plugs and remove spark plugs from engine bef ore Inita lllng gear housing onto drive shalt houllngFailure to follow thi warning could result In accidental engine slartlng and po lble InJuryITit engine toruli up position and engage the tillioe lever2Install nylon tube and rubber seal onto dri'e sha ft (Figure
5Shift gcar housi ng into forward gear (Figure 9) and plaee sh ift lever (Figure 10) in forward gear posit ion
8Shill Shall (Rotate Full Clockwise)
Figure 9Placing Gear Housing in Forward Gear
aRubber Seal (Splined Portion toward Nylon Tube)ylon Tube, Splined