G3408C and G3412C Engines Caterpillar

Illustration 1	g01402001
(2) Camshaft

Note: Do not use a torch to heat the camshaft drive gear.

(1) Maximum temperature of the camshaft drive gear for installation on the camshaft ... 315 °C (599 °F)

(A) Distance between the camshaft drive gear and the camshaft ... 0.640 to 0.140 mm (0.0252 to 0.0055 inch)

(B) Camshaft bearing journal

Diameter of the bearing journals for a new camshaft ... 69.850 ± 0.013 mm (2.7500 ± 0.0005 inch)

Bore in the front sleeve bearings and the rear sleeve bearings for a new camshaft after installation ... 69.969 ± 0.048 mm (2.7547 ± 0.0019 inch)

Bore of inner sleeve bearings for a new camshaft after installation ... 69.982 ± 0.061 mm (2.7552 ± 0.0024 inch)

(C) Protrusion of dowel ... 8.76 ± 0.25 mm (0.345 ± 0.010 inch)

(D) Plate

Thickness of a new plate ... 4.65 ± 0.03 mm (0.183 ± 0.001 inch)

Thickness of the groove in the new camshaft ... 4.83 ± 0.06 mm (0.190 ± 0.002 inch)

End play of camshaft ... 0.10 to 0.25 mm (0.004 to 0.010 inch)

Illustration 2	g01402016

(F) Specified camshaft lobe lift

Exhaust lobe ... 8.900 mm (0.3504 inch)

Inlet lobe ... 6.700 mm (0.2638 inch)

In order to determine the actual camshaft lobe lift, use the following procedure:

1. Measure camshaft lobe height (E) .

2. Measure base circle (G) .

3. Subtract the base circle (G) from the camshaft lobe height (E) . The difference is the actual camshaft lobe lift.