1978 Johnson 55 HP Outboards Service Manual, Page 93Get this manual
oOil and place new "0" ring on driveshaft seal housingLocate bearing cone squarely in hole in gearcasePosition shim(s) on top of conePlace seal protector (Special Tool #316614) over driveshaft splines and slide seal housing onto driveshaftSee Figure 6-50pDip screws in OMC Gasket Sealing Compound and tighten to torque specified in Section 2 83104
Figure 6-51Pressure Testing Gearcase 16-18 psi (110-124 kPa)If pressures does not hold, submerge gearcase in water and check for source of leakageMake necessary repairs and repeat testcScrew in vacuum testerPump out to 3"-5" of mercury and see if vacuum holdsThen pump out to 15" of mercury and checkIf gearcase fails to hold on either test put oil around suspected sealIf leak then stops or oil is drawn in, that seal is defectiveWhen gearcase checks out OK, refill with lubricantSee Section Lubrication ChartdCoat propeller shaft splines with OMC Gasket Sealing CompoundPlace thrust bushing in propeller and then slide assembly onto propeller shaftInstall thrust washer on shaft splineInstall and tighten propeller nut finger tight and then tighten to align next cotter pin holeThe propeller shaft should turn freely (engine in neutral) after propeller is installedInstall cotter pin (use new pin if necessary) bending' ends over nut