Usage:
Start By:
a. remove valve cover
Fluid Spillage Containment
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to "Tools And Shop Products Guide", NENG2500 for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose fluids according to local regulations and mandates.
1. Remove bolts (1) and the washers that hold rocker shaft assembly (2) in position.
2. Remove rocker shaft assembly (2). Remove the O-ring seal from the rear rocker arm support bracket.
3. Put identification marks on push rods (3) as to their location in the engine. Remove the push rods.
NOTE: The following steps are for the installation of the rocker shaft assembly and push rods.
4. Loosen the adjusting screws (4) on the rocker arms for valve clearance. This will prevent a bent valve or push rod during installation of the rocker shaft assembly.
5. Install push rods (3).
NOTE: The O-ring seal in the rear support must be installed new each time the bolt is removed from the rear support bracket.
6. Put rocker shaft assembly (2) in position on the cylinder head.
| NOTICE |
|---|
Make sure the dowels on each end of the rocker shaft assembly are in alignment with the holes in the cylinder head. |
7. Put 4C-5593 Anti-Seize Compound on all of bolts (1) that hold the rocker shaft assembly in position except for bolt (10) that goes through the rear rocker arm support bracket. Install the bolts in the rocker shaft assembly.
8. Tighten bolts (1) for the rocker shaft as follows:
a. Tighten all the bolts in number sequence to a torque of 155 N·m (115 lb ft).
b. Tighten all the bolts again in number sequence to a torque of 250 ± 17 N·m (185 ± 13 lb ft).
c. Last, tighten bolts again in number sequence (hand tighten only to a torque of 250 ± 17 N·m (185 ± 13 lb ft).
9. The assembled length of springs at both ends of rocker shaft must be 1.50 ± 0.25 mm (.059 ± .010 in). Remove or install washers behind springs to change the assembled length of the springs.
10. Make adjustments until the inlet valve clearance is 0.38 mm (.015 in) and the exhaust valve clearance is 0.64 mm (.025 in). See the topic "Valve Clearance Setting" in Testing & Adjusting. Tighten the locknuts (2) for the adjusting screws (1) to a torque of 29 ± 7 N·m (21 ± 5 lb ft.
End By:
a. install valve cover.
Disassemble & Assemble Rocker Shaft
Start By:
a. remove rocker shaft and push rods
1. Remove O-ring seal (1) from the rear support bracket.
NOTE: A replacement of the O-ring seal must be made each time and head bolt is removed from the rear support bracket.
2. Remove retainer ring (6), washer (5), spring (4) and washer (3) from each end of rocker shaft. Remove rocker arm (2).
3. Remove pin from rear support bracket with a hammer and punch. Remove rear support bracket (7) from shaft.
4. Remove remainder of rocker arms, springs, washers and brackets.
5. Remove plugs from each end of the shaft if necessary.
NOTE: The following steps are for the assembly of the rocker shaft.
6. Install rocker arms (2), brackets (8), washers (5) and springs (4) on the rocker shaft.
7. Install rear support bracket (7) on rocker shaft. Make sure hole in rear support bracket is in alignment with hole in rocker shaft.
8. Install pin (9) through bracket and shaft with a hammer.
9. Pin (9) must extend 9.60 mm (.378 in) above the bracket.
10. Install O-ring seal (1) in the rear support bracket. Install rocker arm (2), washer, spring, washer and retainer ring on the rocker shaft.
11. Install the plugs in each end of the rocker shaft if they were removed.
End By:
a. install rocker shaft and push rods