1974 Johnson 40 HP Outboard Motors Service manual, Page 63Get this manual
driveshaCt pinion gear rotates constantly with the operation of the motor and drives two bevel gears whic revolve freely on the propeller shaftThe clutch shifter dog is splined to the propeller shaft In neutral operation, the shifter dog with detent spring and balls is cent ered between the two gea s, which revolve in opposite directions, and remains motionlessIn forward or reverse operation, the shift leve causes the shifter dog to engage either gearPower is then transmitted from the rotating gear, through the hifter dog, to the propeller shaft and propeller REMOVAL OF GEARCASE
It Is possi ble to remove the lower gearcase as sembly without removing the power head Crom the motor However, if disassembly of the exhausthousing is required, it Is necessary first to remove the power headSee Section for instructions The gear case assembly may be removed from the exhaust housing and power head as follows: Fi gure 6-5Gearcase Attaching Screws
REMOVAL OF EXHAUST HOUSING, STEERING AND STERN BRACKETS