Usage:
All Caterpillar Engines
New turbochargers that are used in production are designed with thinner compressor wheel blades for better efficiency. See Illustration 1. These thinner compressor wheel blades are more susceptible to damage during routine service. There has been a significant increase in reports of this problem on 3406B Truck Engines.
Increased care needs to be given when handling Caterpillar turbochargers during service operations. Damage to the compressor wheel blades can result from light contact with the compressor housing. This contact may occur when rotating the compressor housing to adjust the valves. If the compressor wheel is visibly damaged, the compressor wheel must be replaced. See Illustration 2. When replacing a damaged compressor wheel, check to be sure the turbocharger shaft is straight.
Illustration 1. Turbocharger compressor wheel blades.
Illustration 2. Bent compressor wheel blades.