18045 1 Mercruiser WASHER

The flow of cooling air needed to cool the engine coolant and the hydraulic oil is provided by a 54-inch (137 cm) fan mounted in the left side of the air box. The engine radiator and the hydraulic oil cooler are mounted in two of the other walls of the air box. The fan pulls cooling air through the radiator and oil cooler and discharges the air out the left side of the air box.
ALWAYS CHECK THAT THE AIR BOX COVER IS CLOSED BEFORE STARTING THE ENGINE. COOLING AIR WILL NOT FLOW THROUGH THE RADIATOR OR OIL COOLER UNLESS THE AIR BOX COVER IS CLOSED.
The cooling fan is belt driven by the engine. A drive sheave is turned by the engine through a stub shaft bolted to the engine crankshaft. A drive belt band transfers the power from the drive sheave to the fan sheave keyed to the fan shaft. When the belt turns the fan sheave, the sheave turns the fan shaft and the attached fan.The fan shaft is supported by two pillow block bearings that must be individually lubricated.Removing The Drive Sheave
STARTING OF THE ENGINE CAN CAUSE INJURIES TO ANYONE WORKING ON THE FAN DRIVE ASSEMBLY. SHUT THE ENGINE DOWN, TAG THE ENGINE CONTROL AND LOCK THE MAIN BATTERY SWITCH AT "OFF" BEFORE WORKING ON THE ASSEMBLY.
1. Remove the belt guard from in front of the engine and unbolt and open the air box door. 2. Turn the adjusting nut on the tensioner and idler bushing assembly to relieve the tension in the fan drive belt band.3. Slide the belts off the drive sheave and secure them out of the way. 4. Remove the bolts from the bushing and reinsert them into the tapped holes. Turn the bolts alternately and evenly until the bushing is free of the shaft, then remove the sheave.5. Slide the sheave off the shaft.Installing The Drive Sheave
1. Position the sheave and bushing on the front stub drive assembly and install the bolts through the untapped holes in the bushing. Tighten the bolts to 112 ft.-lbs. (153 Nm).2. Position the drive belt band on the sheaves. 3. Turn the adjusting nut on the tensioner and idler bushing assembly until a force of 60 pounds (27 kg) applied to the belt band midway between the sheaves produces a belt deflection of 7/16 inch (11 mm).4. Install the belt guard and close and bolt the air box door.Removing The Fan Drive Assembly
STARTING OF THE ENGINE CAN CAUSE INJURIES TO ANYONE WORKING ON THE FAN DRIVE ASSEMBLY. SHUT THE ENGINE DOWN, TAG THE ENGINE CONTROL AND LOCK THE MAIN BATTERY SWITCH AT "OFF" BEFORE WORKING ON THE ASSEMBLY.
1. Remove the fan drive belt band (see page 2.0-19, steps 1 through 3).2. Disconnect the lubrication hose from the outboard bearing.3. Unbolt and remove the air box cover and the fan access guard.4. Attach a lifting device to the fan. Support the weight of the fan, remove the fan mounting bolts, then lower the fan to the bottom of the air box. Tie-off the fan to the air box to prevent the fan from tipping outboard.5. Attach the lifting device to the fan mount, remove the mounting bolts, move the mount rearward until the idler sheave mounting arm is clear, then move the mount and attached bearings and shaft out the left side of the air box.6. Attach the lifting device to the fan and move the fan out the left side of the air box.Removing The Bearings, Sheave And Shaft From The Fan Mount
1. Adequately support the weight of the bearings, sheave and shaft, unbolt the bearings and lower the assembly to the ground. 2. Mark on the shaft the position of the bearings then loosen the setscrews in the outboard bearing and remove the bearing from the shaft. 3. Mark on the shaft the position of the bushing. Remove the bolts from the sheave bushing and install the bolts in the bushing tapped holes. Turn the bolts alternately and evenly until the bushing is free of the sheave, then remove the bushing and sheave from the shaft.4. Loosen the setscrews in the remaining bearing and slide the bearing off the shaft.Installing The Bearings, Sheave And Shaft Onto The Fan Mount
1. Align the inboard bearing with the mark on the shaft, then tighten the bearing setscrews. 2. Position the key, slide the sheave onto the shaft, align the bushing with the mark on the shaft, install the bolts through the untapped holes and into the sheave. Making sure the bushing remains aligned with the mark, tighten the bolts to 112 ft.-lbs. (153 Nm). 3. Align the outboard bearing with the mark on the shaft, then tighten the bearing setscrews.4. Adequately support the weight of the bearings, sheave and shaft, move the assembly into position on the fan mount, then install the bearing mounting bolts.Installing The Fan Drive Assembly
STARTING OF THE ENGINE CAN CAUSE INJURIES TO ANYONE WORKING ON THE FAN DRIVE ASSEMBLY. SHUT THE ENGINE DOWN, TAG THE ENGINE CONTROL AND LOCK THE MAIN BATTERY SWITCH AT "OFF" BEFORE WORKING ON THE ASSEMBLY.
1. Attach a lifting device to the fan, move the fan into position in the air box, then tie-off the fan to the air box.2. Attach the lifting device to the fan mount, move the fan mount into position in the air box, then install the mounting bolts.3. Attach the lifting device to the fan, move the fan into position on the shaft flange, then install the mounting bolts.4. Install the drive belts (see page 2.0-20, steps 4 through 6).5. Connect the lubrication hose to the outboard bearing.6. Check the alignment of the fan with the air box. The fan should extend 2 1/2 inches (6.3 cm) into the air box and should have a 1/4 inch (6.3 mm) clearance between the tips of the blades and the wall of the air box. Turn the fan through at least one full revolution to be sure the fan blades clear the air box wall at