1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 271Get this manual
11Remove the pinion and driveshaft from the gearcase as follows: Pull up on the shift rod to engage forward gear positionUsing driveshaft holding socket OMC Special Tool PIN 312752 and 1116" openend wrench, back the pinion nut off the driveshaftPad the handle of the wrench to prevent damage to the gearcaseThe driveshaft to pinion taper is locking taperIf necessary, use OMC Special Tool PIN 387206 (Puller) CD and OMC Special Tool PIN 325867 (Backing Plate) Q) to break the lockInstall the tools as shown by clamping them around the driveshaft with the set screw aligned with the impeller drive pin slot and then tightening he set screw into the slotAlternately tighten the two vertical screws against the backing plate inserted between the puller and the gearcase until the driveshaft pops loose from the pinionRemove the driveshaft with the driveshaft bearing housingand shim(s) thrust washer and thrust bearing from the gearcaseReach inside the gearcase and remove the pinionIt may be necessary to pull up on the shift rod to gain enough clearance to remove the pinion