C280-16 Generator Set Engine for Nuclear Applications Caterpillar

Camshaft Timing

Camshaft Timing Check

1. Remove the rear camshaft inspection cover from the side of the engine.

2. Put the No. 1 piston at the top center position on the compression stroke. Refer to Finding the Top Center Position for the No. 1 Piston.

3. With the No. 1 piston on the compression stroke, install the crankshaft timing pin. After you install the crankshaft timing pin, remove the camshaft timing pin from the camshaft timing pin's storage positions.

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Illustration 1	g01194239
Installation of camshaft timing pin (1) Camshaft timing pin (2) Camshaft

4. Install camshaft timing pin (1) through the timing pin hole and into the hole in camshaft (2). In order for the engine to be timed correctly, the camshaft timing pins must fit into the holes in both of the camshafts.

5. If both of the timing pins cannot be installed into the holes in the camshafts, the engine is not in time and the camshaft position must be adjusted. Refer to Timing Adjustment of the Camshaft.

Timing Adjustment of the Camshaft

Note: Before you make any timing adjustments, the timing must be checked in order to determine whether any adjustment is necessary. Refer to the section Camshaft Timing Check for this procedure.

If the Camshaft Timing Check procedure indicates that the camshaft is not in time with the crankshaft, the camshaft drive gear must be removed and the camshaft must be rotated. Perform steps 1 through 9 if adjustment of the camshaft is necessary.

1. Put the No. 1 cylinder in the top center position on the compression stroke and install the crankshaft timing pin. Remove all of the valve covers.

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Illustration 2	g01447105
Rocker arm shaft (typical example) (1) Bolts (2) Rocker arm shaft

2. Loosen bolts (1) that hold rocker arm shaft (2) in place, until all of the rocker arms are free from the valve bridges.

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Illustration 3	g01194242
Rear end of the engine (typical example) (3) Camshaft drive gear covers

3. Remove the crankshaft timing pin and camshaft drive gear covers (3) from the rear housing.

4. Remove the speed/timing wheel and the spacer from the camshaft gear.

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Illustration 4	g01166866
Camshaft drive gear (4) Camshaft drive gear (5) Bolts (6) Bolt (7) Washer (8) Plate (9) Speed/timing wheel (10) Primary speed/timing sensor (11) Secondary speed/timing sensor

5. Loosen camshaft drive gear (4) by using the following procedure:

   1. Use a 6V-6080 Torque Multiplier Gp and a 5P-1748 Socket and loosen bolt (6) .

   2. Remove bolt (6) and washer (7). Remove bolts (5) and plate (8) .

   3. Refer to Illustration 4. Put washer (7) between the camshaft and plate (8). Install bolt (6) finger tight.

   4. Install bolts (5) finger tight.

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   Sudden movement of camshaft drive gear can occur when the camshaft drive gear is pulled off the taper of the camshaft. To prevent possibly personal injury, be sure that the bolt is installed (finger tight) to restrict the movement of the camshaft drive gear when the camshaft drive gear is pulled off of the taper of the camshaft.

   5. Tighten bolts (5) evenly in order to pull camshaft drive gear (4) off the taper of the camshaft.

   6. Fasten a hoist to the camshaft drive gear (4). Remove the following components: bolts (5), bolt (6), plate (8), washer (7) and camshaft drive gear (4). The weight of the camshaft drive gear is 35 kg (77 lb).

6. Install the crankshaft timing pin. Remove the camshaft timing pin from the storage location.

7. Put the camshaft timing pin in the timing pin hole, and turn the camshaft until the timing pin goes into the hole in the camshaft.

8. Repeat the procedure for the other camshaft, if necessary.

9. After both of the camshafts are in time with the crankshaft, install the camshaft drive gear (4). Use the following procedure:

   1. Fasten a hoist to the camshaft drive gear (4). The weight of the camshaft drive gear is 35 kg (77 lb). Position the camshaft drive gear and put the plate (8) in position on the drive gear. Install bolts (5) .

      Note: Be sure that both the gear and the camshaft tapers are clean and dry.

   2. Assemble speed/timing wheel (9) and the spacer. The extra tooth on the speed/timing wheel must be close to primary speed/timing sensor (10). Leave the 12 bolts loose so that the speed/timing wheel can be rotated.
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   Illustration 5	g01182702
   (9) Speed/timing wheel (10) Primary speed/timing sensor (12) First tooth after the extra tooth

   3. Rotate the speed/timing wheel until the centerline of the first tooth after the extra tooth is aligned with the centerline of the primary sensor.

   4. Tighten the 12 bolts.

   5. Put 4C-5593 Anti-Seize Compound on the threads of bolt (6). Install washer (7) and bolt (6). Tighten bolt (6) by hand.

   6. Remove the crankshaft timing pin and the camshaft timing pin.

   7. Turn the flywheel in the opposite direction of normal rotation for a minimum of 20 degrees.

   Note: Prelube the engine before you rotate the crankshaft in order to perform service work. Rotating the crankshaft before prelube may cause damage to the crankshaft bearings if the mating surface is dry.

   8. Turn the flywheel in the direction of normal engine rotation until the crankshaft timing pin can be reinstalled in the crankshaft. This procedure holds the backlash in the timing gears in the direction of normal engine rotation.

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   NOTICE
   If the crankshaft timing pin location is missed, do not turn the flywheel in the opposite direction in order to install the crankshaft timing pin.

   Note: If the crankshaft timing pin location is missed, repeat Steps 9.g and 9.h.

   9. Install the camshaft timing pin in order to verify the camshaft position. In order to prevent damage to the timing pins, remove the crankshaft timing pin and the camshaft timing pin before you tighten bolt (6) .

   10. Use a 6V-6080 Torque Multiplier Gp and a 5P-1748 Socket, and tighten bolt (6) to a torque of 2000 ± 275 N·m (1480 ± 200 lb ft).

   11. Use a hammer to strike plate (8). Repeat Step 9.j.

   12. Repeat Step 9.k, until there is no movement of the gear on the shaft at full torque.

10. Repeat the timing check procedure for the camshaft in order to verify the correct crankshaft to camshaft timing. Refer to the section Camshaft Timing Check. If the camshaft timing is not correct, repeat the camshaft's timing adjustment procedure.

11. If necessary, repeat the procedure for the other camshaft.

12. Remove the crankshaft timing pin and camshaft timing pin. Return the pins to the storage locations. Install the camshaft inspection covers on the sides of the cylinder block.

13. Install the camshaft drive gear covers (3) on the rear housing.

14. Tighten the bolts that hold the rocker arm shafts in position, and adjust the valve lash.

15. Install the valve covers.