2001/06/01 Caterpillar

Truck Engines:

3406E (S/N: 1LW1-UP; 2WS1-UP; 5DS1-UP; 1MM1-UP; 5EK1-UP; 6TS1-UP)

C-15 (S/N: 6NZ1-UP)

C-16 (S/N: 7CZ1-UP)

Testing and Adjusting, RENR2307-00, "C-15 and C-16 Truck Engines", "Electronic Unit Injector - Adjust"Testing and Adjusting, SENR1273-03, "3406E Engine", "Unit Injector Adjustment"Testing and Adjusting, SENR5017-01, "3406E Truck Engine", "Electronic Unit Injector - Adjust"Testing and Adjusting, SENR5578-01, "3406E Diesel Truck Engine", "Unit Injector Adjustment"

The torque of the adjusting screw locknut for the unit injector has been changed. The torque was 81 ± 10 N·m (60 ± 7 lb ft). The new value for the torque of the adjusting screw locknut has been increased to 100 ± 10 N·m (74 ± 7 lb ft). The new torque should be used only if the unit injectors require adjustment. The change is shown in the text that follows.

Table 1

Tools Needed
Part Number	Part Name	Quantity
9U-7227	Injector Height Gauge	1

Illustration 1	g00294868
Injector Mechanism (1) Rocker arm (2) Adjusting screw (3) Locknut (4) 9U-7227 Injector Height Gauge

To make an adjustment to the unit injectors on cylinders 3, 5, and 6 use the following procedure:

1. Put the No. 1 piston at the top center position on the compression stroke. Refer to Testing and Adjusting, "Finding Top Center Position for No. 1 Piston".

2. Injector height gauge (4) is used in order to obtain a dimension of 78.0 ± 0.2 mm (3.07 ± 0.01 inch). The dimension is measured from the top of the unit injector to the machined ledge of the fuel injector body.

3. Turn unit injector adjusting screw (2) clockwise until the correct height is obtained.

4. Hold the adjusting screw in this position and tighten locknut (3) to a torque of 100 ± 10 N·m (74 ± 7 lb ft).

5. To make an adjustment to the unit injectors on cylinders 1, 2, and 4, remove the timing bolt. Turn the flywheel by 360 degrees in the direction of engine rotation. The direction of engine rotation is counterclockwise, as the engine is viewed from the flywheel end. This will put the number 1 piston at the top center position on the exhaust stroke.

6. Repeat Steps 3 through 4.

7. Remove the timing bolt from the flywheel after all the unit injector adjustments have been made. Reinstall the timing cover.