3508, 3512 and 3516 Generator Set Engines Caterpillar

Removal Procedure

Start By:

1. Remove the valve covers.

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Illustration 1	g00605234

1. Remove bolts (1). Remove rocker shaft assembly (2).
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   Illustration 2	g00636958

   Note: Mark the pushrods for identification of location upon assembly.

   Note: Some engines do not have dowels.

2. Remove bridge assemblies (3) from dowels (4).

3. Remove pushrods (5) from the cup of valve lifters (6).

Installation Procedure

1. Install rocker shaft assembly (2) and pushrods (5) in the reverse order of removal.

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   NOTICE
   Ensure that the crankshaft and the camshafts are in time with each other. Also ensure that the adjustment screws in the rocker arms are loosened completely before the bolts on the rocker shaft are tightened or damage to the valves and the pistons may occur.

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   NOTICE
   If the rocker shaft is not positioned correctly, the oil supply to the sleeve bearings in the rocker arm will be shut off. This will cause seizure of the bearings and severe damage to the engine. Be sure to orient the rocker shaft in the correct position.

   1. Loosen the adjustment screw and the jam nut on bridge assemblies (3).

   2. Apply clean engine oil to the following items: dowels (4), the receptacle of the bridge for the dowels and the uppermost contact surface of bridge assemblies (3).

   3. Place the bridge assembly into position on the dowel. Apply 1 to 14 N·m (1 to 10 lb ft) of downward force on the uppermost contact surface of the bridge assembly. While you apply the force, turn the adjustment screw until the adjustment screw contacts the valve stem.

   4. Turn the adjustment screw for an additional 20 to 30 degrees (1/3 to 1/2 of the hex). This will straighten the dowel in the guide. This will also compensate for a lack of clearance (slack) in the threads.

   5. Hold the adjustment screw in position and tighten the jam nut to a torque of 30 ± 4 N·m (22 ± 3 lb ft).

   6. Apply clean engine oil to pushrods (5) and the cups of valve lifters (6). Place the pushrods into position on the valve lifters.

   7. Place rocker shaft assembly (2) in position. Make sure that the rocker arms and pushrods (5) are aligned. Install bolts (1). Tighten the bolts to a torque of 120 ± 20 N·m (90 ± 15 lb ft).

   8. Adjust the valve bridge and the valve lash according to Testing and Adjusting, "Valve Lash and Valve Bridge Adjustment".

   9. Adjust the fuel injection pump according to Testing and Adjusting, "Fuel Injector Adjustment".