1987 Johnson/Evinrude CU Outboards 35A thru 55 Service Manual, Page 231Get this manual
Driveshaft Shimming Using Tool PI 315787 The driveshaft pinion is precisely meshed with the forward and reverse gears by the use of shim or shims between the driveshaft bearing housing and thrust washerWhen installing new thrust bearing or washer, bearing housing, pinion, or driveshaft, it is necessary to gauge and select the proper shims to restore factory clearance 1 1Degrease pinion and driveshaft tapers prior to assemblyNote
1Clean the driveshaft and pinion in clean solvent and dry thoroughlyAssemble the pinion to the driveshaft and tighten the pinion nut to torque of 40-45 ftIbs(54-60 Nm)
2Place OMC Shim Gauge, PIN 315767, in vise as shownSelect approximately 0.020 in(0,508 mm) of driveshaft shimsClean the shims in solvent and dry thoroughlyCarefully measure shims using micrometerPosition the shims between the drives haft and shim gauge as shown