Engine 01 1 2 3 4 5 6 7 8 01/18/2010 f151148 1. Abrasion 2. Chunk-out 3. Improper Install 4. Cracking 5. Pilling 6. Uneven Rib Wear 7. Misalignment 8. Gravel Penetration Fig. 2, Damaged Belts NOTE: At engine overhaul, and whenever the engine has been removed, inspect the lower and upper isolators (Refs. 6 and 7), and replace them if they are worn. Western Star Maintenance Manual, September 2015 01/3