PLATE-THRUST 4N0798 - Caterpillar

Timing Check
Table 1
Tools Needed     Quantity    
9S-9082 Engine Turning Tool     1    
Illustration 1 g00284801
Location of timing pins (typical example) (1) Timing hole (2) Timing pin
Remove rear camshaft covers from both sides of the engine.
Refer to Finding Top Center Position For No. 1 Piston.Note: When the timing bolt is installed in the flywheel, it is not necessary to remove the No. 1 valve cover in order to find the compression stroke. Both rear camshaft covers must be removed in order to check the timing.
When the timing bolt is installed in the flywheel, look at the rear end of the camshaft. If the timing ring is visible, then the No. 1 piston is on the compression stroke. If the timing ring is not visible, feel the back of the camshaft for the groove. If the groove is at the back of the camshaft, the flywheel must be turned by 360 degrees in order to put the No. 1 piston on the compression stroke.
Illustration 2 g00284802
Installation of timing pins (typical example) (2) Timing pin (3) Camshaft (right hand)
When the timing bolt is installed in the flywheel and the No. 1 piston on the compression stroke, remove the timing pins (2) from the storage positions.
Install the timing pins (2) through the timing holes (1) in the engine block. Install the timing pins into the groove in the camshaft (3) on each side of the engine. In order to time the engine correctly, the timing pins must fit into the groove of each camshaft.
If the timing pins (2) do not engage in the grooves of both camshafts, the engine is not in time, and one or both camshafts must be adjusted.
Both camshafts are adjusted in the same manner. Refer to Testing And Adjusting, "Timing Adjustment" for the procedure to put the camshafts in time with the crankshaft.
If a camshaft is out of time more than 18 degrees, the valves can make contact with the pistons. This will cause damage that will make engine repair necessary.
Timing Adjustment
Table 2
Tools Needed     Quantity    
9S-9082 Engine Turning Tool     1    
6V-3010 Puller Group     1    
8S-9089 Bolts     2    
5P-1076 Hard Washers     2    Note: The timing must be checked before the timing adjustments are made. See Testing And Adjusting for this procedure.After the Timing Check procedure is complete, the timing bolt will be engaged in the flywheel. The No. 1 piston will be at the top center (TC) position.
Illustration 3 g00284803
Loosen the rocker shafts (typical example). (1) Bolt (2) Rocker shaft
Illustration 4 g00284804
Camshaft drive gears (right hand side) (3) Drive gear (4) Plate (5) Bolt
Remove all of the valve covers on the side for the adjustment of the camshaft. Now loosen bolts (1) that hold rocker shafts (2) to valve cover bases until all rocker arms are free from the injectors and the valves.Note: The above procedure must be done before camshaft drive gear (3) is pulled off the camshaft taper.
Remove the covers from the flywheel housing.
Illustration 5 g00284805
Camshaft drive gears