3412C GENERATOR SET ENGINE Caterpillar


Rocker Shaft Assembly

Usage:

Remove Rocker Shaft Assembly

Start By:

a. remove valve covers

1. Use tooling (A) to disconnect three adapters (4) and (5).

2. Remove three nuts (2) and locknuts (3).

3. Remove three fuel lines (1).

4. Remove the cover from the flywheel housing and install tool (B). Use tool (B) to turn the crankshaft to release any pressure against the rocker arms.

5. Use tool (C) to move the rocker arms away from push rods (6) far enough so the push rods can be removed.

6. Put identification on valve bridges (9) as to their location for correct installation. Remove valve bridges (9).

7. Remove bolts (7) and rocker shaft assembly (8).

Install Rocker Shaft Assembly

1. Put rocker shaft assembly (8) in position.

2. Put clean engine oil on bolts (7). Install three bolts (7).

3. Use the following procedure to tighten bolts (7).

a. Tighten bolts (10) through (15) in numerical sequence to 280 ± 27 N·m (210 ± 20 lb ft).

b. Tighten bolts (10) through (15) in numerical sequence to 440 ± 20 N·m (320 ± 15 lb ft).

c. Do Step 3b again to make sure all the bolts are tightened to the correct torque.

4. Put clean engine oil on the valve bridge dowels. Install valve bridges (9) in their original positions on the engine.

5. Use tool (A) to make sure there will be no pressure against push rod (16) and rocker arm (17). Use tool (B) to pull rocker arm (17) away from push rod (16). Put push rod (16) in position under the rocker arm. If the rocker arm can not be moved enough to put the push rod in position, turn the crankshaft with tool (A).

6. Make an adjustment of the valves to have a clearance of .038 mm (.015 in) for intake and 0.76 mm (.030 in) for exhaust. See VALVE CLEARANCE SETTING in TESTING AND ADJUSTING.

7. Make sure the O-ring seal is in position on the adapter. Put clean engine oil on the O-ring seal. Put adapters (4) and (5) with fuel lines (1) in position in the valve cover base.

8. Install locknuts (3) and nut (2). Tighten locknuts (3) to a torque of 30 ± 7 N·m (22 ± 5 lb ft). Tighten nut (2) to a torque of 41 ± 7 N·m (30 ± 5 lb ft).

9. Use tool (C) to tighten adapters (4) and (5) to a torque of 41 ± 7 N·m (30 ± 5 lb ft).

End By:

a. install valve cover

Disassemble Rocker Shaft Assembly

Start By:

a. remove rocker shaft assembly

1. Remove retainer (3), washers (2) and rocker arm (4) from the rocker shaft assembly.

2. Make sure dowel (1) is free of oil.

3. Put tooling (A) in position on dowel (1). Pull rocker arm (6) away from bracket assembly (5). Remove the dowel with tooling (A). Remove bracket assembly (5).

4. emove rocker arms (9), spring (8) and brackets (7). Use tooling (A) to remove the dowel that holds bracket assembly (6) on the rocker shaft.

5. Remove nuts (10) and screws (11) from the rocker arms if a replacement is necessary.

6. Remove plug (12) from rocker shaft (13) if a replacement is necessary.

Assemble Rocker Shaft Assembly

NOTE: Make sure all the parts of the rocker shaft assembly are clean before assembly.

1. Install plug (1) in the end of rocker shaft (2). Install the plug to a depth of 12.7 ± 1 mm (.50 ± .04 in) from the end of the shaft.

2. Do Step 1 again for the plug in the other end of the shaft.

3. Install screws (4) and nuts (3) on each of the rocker arms.

4. Put the retainer, the original washers and rocker arm (8) in position on the rocker shaft. Put bracket assembly (5) in position on the shaft so that the hole in the bracket assembly is in alignment with the larger hole in the shaft.

5. Install the dowel that holds the bracket assembly in place.

6. Install the rest of the rocker arms, springs (9) and brackets (6). Push rocker arm (7) to the left of the large hole (10). Install the other bracket assembly. Make sure hole (12) in the bracket assembly is in alignment with hole (10).

7. Install dowel (11) through the bracket assembly and into hole (10).

8. Dowel (11) must be installed so that dimension (X) is 12.7 ± 1 mm (.50 ± .04 in).

9. Install the last rocker arm (13), the original washers (14) and retainer (15).

10. Use feeler gauge (16) to check the clearance between the rocker arm and the washers. Add or subtract washers as necessary until the clearance is 0.3 to 1.4 mm (.012 to .055 in). Check the clearance at the other end of the rocker shaft assembly.

End By:

a. install rocker shaft assembly

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