1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 236Get this manual
CLAMPSWIVEL BRACKETSDRIVE SHAFT HOUSING
6First replace two (2) bolts (M8x.98) into mount and then replace washer and nut7Torque two (2) bolts to 15 lb-ft (20.3 Nm)8Torque nut to 32.5 lb-ft (44 Nm)9Re-install driveshaft housing covers
a-Nut and WasherTorque to 32.5 lb-ft (44 Nm) b-Bolts (2) Torque to 15 lb-ft (20.3 Nm)
RemovalInstallation of Clamp Bracket Assembly
1Shift outboard into reverse2Remove driveshaft housing covers3Lay outboard on backside4Disconnect shift shaft5Remove upper mount bolts and nuts6Remove lower mount covers