DRIVE BELTS Each belt uses an automatic tensioner. In the high position, Figure 17, there are two idler pulleys in the primary loop: one between the coolant pump pulley and the tension idler; the other between the crankshaft pulley and the fan hub. 18 This engine can be configured to accommodate either the conventional chassis or the low cab forward (LCF) design. Depending on the vehicle, the fan location may be high or low on the fan bracket. Two poly-V belts drive the front engine accessories. The outer, primary belt (10 or 12 ribs) drives the coolant pump and fan hub from a pulley on the crankshaft flange nested in the vibration damper.
The inner, secondary belt (six ribs), driven by the crankshaft vibration damper, drives the alternator and refrigerant compressor. 17 Figure 18 — Primary and Secondary Drive Belts — LCF Chassis Figure 17 — Primary and Secondary Drive Belts — Conventional Chassis In the low position, Figure 18, the idler between the damper and fan pulleys is omitted. Page 24 DESCRIPTION AND OPERATION 1. EGR Cooler Outlet Pipe 2. Fan Drive 3. EGR Mixer 4. Belt Tensioner (Alternator/Refrigerant Compressor Belt) 5. Alternator (Pad Mount) 6. Refrigerant Compressor (Pad Mount) 7. Belt Tensioner (Fan Drive/Water Pump Belt) 8. Water Pump 9. Venturi 10. Differential Pressure Sensors 1. EGR Cooler Outlet Pipe 2.
Fan Drive 3. EGR Mixer 4. Belt Tensioner (Alternator/Refrigerant Compressor Belt) 5. Alternator (Pad Mount) 6. Refrigerant Compressor (Pad Mount) 7. Belt Tensioner (Fan Drive/Water Pump Belt) 8. Water Pump 9. Venturi 10. Differential Pressure Sensors