3406E Truck Engine Caterpillar

Illustration 1	g00288837
Drive gear (typical example)

Note: Caterpillar may use air compressors that have a tapered shaft or a straight shaft. The torque for the nut on the air compressor crankshaft is different for each type of crankshaft. See the following specifications for the proper torque values.

Note: Identify the manufacturer of the air compressor for your particular application.

Bendix Air Compressors

Tapered shaft

Torque the nut for the air compressor crankshaft (1) to the following torque when the air compressor crankshaft is tapered. 160 ± 15 N·m (118 ± 11 lb ft) Tap the gear axially with a soft faced hammer in order to seat the gear onto the tapered crankshaft. Torque the nut for the air compressor crankshaft again to 160 ± 15 N·m (118 ± 11 lb ft).

Straight shaft

Torque the nut for the air compressor crankshaft (1) to the following torque when the air compressor crankshaft is straight. 460 ± 60 N·m (340 ± 44 lb ft)

Wabco 250 Air Compressors

Torque the nut for the air compressor crankshaft (1) to the following torque. 150 ± 5 N·m (111 ± 4 lb ft)

Place an index mark on the nut and turn an additional 60 ± 5 degrees.