SERVICE MGR.
SALES MGR.
PARTS MGR.
SERVICE MGR.
SUBJECT: GEARCASE STUDS AND STUD NUTS - TORQUING, 75 H.P.
(Supplement to Bulletin No. SB-756, dated December 15, 1959)
In some cases where stud nuts have become loosened, the gearcase studs which secure the upper and lower gearcase housing might also become loosened in the lower gearcase. This problem can be caused by striking an underwater obstruction or by excessive vibration due to running with a damaged propeller. The studs, part number 307084, front, and 307085, rear, have a shoulder at the bottom end which must fully seat on the top surface of the gasket, 307086. This gasket fits between the shoulder and the top surface of the lower gearcase. The studs are torqued to 24 ft. lbs.
Whenever you service a 75 H.P. motor, or there is visible sign of impact on the gearcase, check the stud and stud nut torques. This will prevent possible future damage to gears, gearcase housing and the lower unit in general. NOTE: Replace all external tooth stud nut lock washers with the new spring lock washer, part number 307708.
Torquing should be accomplished with a stud driver. Do not attempt to torque these studs with an ordinary 9/16" socket by using two nuts 307160 on the upper ends. Doing so will not guarantee the required torque and may well accomplish nothing more than damaged nuts and/or stud threads.
Torque Studs 307084 and 307085 to 24 ft. lbs.
Torque Nuts 307160 to 18 ft. lbs.
JOHNSON MOTORS
W. W. DeWees
Service Department
WWD:eb
NOTE: Post on your V-4 index - 75 H.P.