1978 Johnson 4HP outboards Service Manual, Page 73Get this manual
DISASSEMBLY OF GEARCASE aRemove propellerbRemove the water pump screws and lift pump and driveshaft from gearcaseRemove water tube grommet from pumpSee Figure 6-4cDrain lubricant from gearcasedDisassembly propeller rubber slip clutch See Figure 6-12 or 6-13eRemove the two screws holding the gearcase head or bearing retainer to the gearcaseRemove gearcase head or bearing retainer by withdrawing the propeller shaftSee Figure 6-12 or 6-13fSlide gearcase head or bearing retainer from propeller shaft and remove oil retainers or seals
gThe standard gearcase pinion gear slides outTo remove the weed less gearcase pinion gear, it is first necessary to remove thrust bearingSee Figure 6-11Tap the gearcase on bench or insert the driveshaft and tap on the end of it to dislodge the bearingPinion gear can then be removed hRemove the driveshaft oil retainer or seal from the top of the gearcase, using seal puller (Special Tool #377565)