OMC Stern Drives And Motors 1964-1986 Repair Manual., Page 354Get this manual
10 STERN DRIVE 10-1 DESCRIPTION
Electromatic gearcases used on OMC drive installations between 1964 and 1977From 1978 through 1981, OMC used mechanical assisted power unit with propeller exhaustSince 1982, the shifting has been by mechanical linkage onlyEach drive contains an upper and lower unitThe drive is presented in the portion of this from Section 10-2 thru 10-21T mechanical assisted power shift and the mechanical drives combined in Sections 10-22 thru 10-60
10-2 EARLY STERN DRIVE UNITS