Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 221Get this manual
7Position gear housing so that the drive shaft is protrudi ng into drive shaft housing8Route speedometer hose up thru shift shaft hole in mid-sectionNOTE: When performing Step 8, if the drive shaft splines wil1 not align with crankshaft splines, place propeller onto propeller shaft and turn it counterclockwise as the gear housing is being pushed toward drive shaft housing 9Move gear housing up toward drive shaft housing,
while aligning upper and lower sh ift shaft splines, and water tube with water tube guide (in water pump body)10Place flat washers onto studs (2 located on either side of drive shaft housing)Start nut on these studs and tighten finger-tight
11 .Start remaining bolts, nuts, and washers at front and rear of gear housingDO NOT tighten bolts or nuts at this time