Engine 01 Safety Precautions 01–02 Engine Belt Inspection DANGER Belt and Pulley Inspection When working on the vehicle, shut down the en- gine, set the parking brake, and chock the tires. Before working under the vehicle, always place jack stands under the frame rails to ensure the vehicle can not drop. Failure to follow these steps could result in serious personal injury or death. Worn or loose drive belts may cause engine over- heating or loss of alternator power. Replace the drive belt if any conditions described in Fig. 2 are found. To inspect a belt, gently twist it to view the belt side- walls and bottom. 1.
Inspect the belt contact surfaces for chips, flak- ing, cracks, discoloration, and other damage. See Fig. 2 . 01–01 Engine Noise Panel Inspection (Noise Emission Control) IMPORTANT: For EPDM rubber drive belts, do not rely on cracking as an indicator of belt wear. EPDM rubber drive belts resist cracking better than neoprene belts. A better indicator of wear on EPDM belts is material loss. If equipped, inspect for torn engine panels. See Fig. 1 for Caterpillar noise panel locations. If the panels are torn, contact your Western Star dealer to have them replaced. Cummins M11, N14, ISC, and ISL engines, and Detroit Diesel Series 60 and DD13 engines do not have engine noise panels. 2.
For EPDM belts, check the belt for material loss, which causes the belt to seat further down in the pulley and to ride directly on the pulley tips. See Fig. 3 . 3. Inspect the pulleys for excessive play or wobble. Excessive play or wobble indicates a failure of the pulley bearing. Check for belt squealing or squeaking. Replace the bearings as necessary. NOTE: If it is difficult to distinguish the location of a supposed bearing noise, place a stetho- scope on the component being checked, not the pulley, to isolate the area from outside interfer- ence. 2 4. Inspect all pulleys for foreign objects, oil, or grease in the grooves.
Belt Tension Inspection Some V-belts use a threaded adjustment, and the ONLY accurate way to check belt tension is to use a belt tension gauge. See your Western Star dealer for this type of adjustment. 1 11/29/95 1. Oil Pan Noise Panel (C10 engine only) 2. Left-Side Noise Panel (3406 engines only) f011040 Serpentine belts are tensioned by spring-loaded idler pulleys that are usually maintenace free. Uneven belt wear can indicate a loose, worn out, or bad bearing on the auto tensioner. A build up of dirt or grime around the front bearing surface of the wheel can indicate a future bearing failure due to inadequate lubrication. Fig.
1, Caterpillar Engine Noise Panels Western Star Maintenance Manual, September 2015 01/1