3126 Truck Engine Caterpillar

Illustration 1	g00291257

(1) Heat the gear for installation. Do not use a torch.

Maximum temperature ... 316°C (600°F)

(2) The following dimensions are located in the area that is shown above.

New thrust washer thickness ... 4.70 ± 0.03 mm (0.185 ± 0.0012 inch)

End play of a new camshaft ... 0.13 ± 0.08 mm (0.005 ± 0.003 inch)

Maximum permissible end play of a worn camshaft ... 0.46 mm (0.018 inch)

(3) Diameter of the camshaft journals ... 65.126 ± 0.013 mm (2.5640 ± 0.0005 inch)

(4) Inlet lobe

(5) Exhaust lobe

(6) Distance between the shoulder of the camshaft and the shoulder of the gear

Total distance ... 4.83 ± 0.05 mm (0.190 ± 0.002 inch)

Illustration 2	g00291256

(7) Camshaft lobe lift

Specified camshaft lobe lift (7)

Exhaust lobe ... 7.459 mm (0.2937 inch)

Inlet lobe ... 9.264 mm (0.3647 inch)

To find the lobe lift, use the procedure that follows:

1. Measure the camshaft lobe height (8) .

2. Measure the base circle (9) .

3. Subtract the base circle that is found in Step 2 from the lobe height that is found in Step 1. The difference is the actual camshaft lobe lift (7) .

Maximum permissible difference between actual lobe lift and the specified lobe lift of a new camshaft ... ± 0.10 mm (.004 inch)