18878A 2 Mercruiser GEAR SET (Pinion and Drive)

The flow of cooling air needed to cool the two engines and the hydraulic oil is provided by a 60-inch fan mounted in the rear wall of the air box. The two engine radiators and the hydraulic oil cooler are mounted in the other three walls of the air box. The fan pulls cooling air through the radiators and oil cooler and discharges the air out the back of the air box.
ALWAYS START ENGINE B (CATERPILLAR 3208) BEFORE STARTING ENGINE A (CATERPILLAR 3412) AND ALWAYS CHECK THAT THE AIR BOX COVER IS CLOSED BEFORE STARTING ENGINE B. COOLING AIR WILL NOT FLOW THROUGH THE RADIATORS UNLESS ENGINE B IS RUNNING AND THE AIR BOX COVER IS CLOSED. THE HYDRAULIC MACHINE CONTROLS WILL NOT OPERATE UNLESS ENGINE B IS RUNNING.
The cooling fan is belt driven by the primary (Caterpillar 3208) engine. A drive sheave is turned by a short coupled drive line that incorporates two universal joints and a sliding spline section. Six drive belts transfer the power from the drive sheave to the fan sheave keyed to the fan shaft. When the belts turn the fan sheave, the sheave turns the fan shaft and the attached fan. The drive sheave rides on a ball bearing and a roller bearing that are lubricatd by grease inside the sheave. The fan shaft is supported by two pillow block bearings that must be individually lubricated. IF THE DRIVE LINE IS DISCONNECTED FROM THE SHEAVE ADAPTER, THE LUBRICANT WILL FLOW OUT OF THE DRIVE SHEAVE.Removing The Drive Sheave And Drive Line Assembly
STARTING OF THE ENGINE CAN CAUSE INJURIES TO ANYONE WORKING ON THE FAN DRIVE. SHUT ENGINE B (CATERPILLAR 3208) DOWN, TAG THE ENGINE CONTROL AND LOCK THE MAIN BATTERY SWITCH AT "OFF" TO WORK ON THE ASSEMBLY.
1. Remove the drive line guard and belt guard. 2. Remove the bolts that hold the drive line to the crankshaft pulley adapter. Let the drive line hang down.3. Loosen the takeup plate bolts only enough to allow the