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Tim, Foreman
Category: Heavy Equipment
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Experience:  23 Years Heavy Equipment and Truck Repairs Shop and Field in the Minning and Construction Industry
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How to ajust c-15 timing and injectors

Customer Question

how to ajust c-15 timing and injectors
Submitted: 8 years ago.
Category: Heavy Equipment
Expert:  Tim replied 8 years ago.

Hello, my name is XXXXX XXXXX will try to help, Can you give ma a Engine ser#, Are you wanting valve and injector adjustment?


Thank you,


Customer: replied 8 years ago.
I dont have ser# XXXXX . can you tell me some info
without ser#
Expert:  Tim replied 8 years ago.

Hello, I will give you the static timming for mxs ser #, the injectors are done with a special tool, did you replace the cam?



View Image

Illustration 1g01106267

Front gear group

(1) Timing marks

(2) Camshaft gear

(3) Adjustable idler gear

(4) Idler gear

(5) Cluster gear

(6) Timing marks

(7) Crankshaft gear

(8) Oil pump gear

The basis for the correct fuel injection timing and the valve mechanism operation is determined by the alignment of the timing for the front gear group. Timing marks (1) and timing marks (6) are aligned in order to provide the correct relationship between the piston movement and the valve movement.

setting back lash for camshaft and, adjustable idler gear

Table 1
Required Tools
Tool Part Number Part Description Qty
A 9U-7255 Gear Gauge (Adjustable Idler) 1
B 9U-7324 Indicator Bracket 1
7H-1942 Dial Indicator 1
3S-3268 Indicator Contact Point 1
7H-1940 Universal Attachment 1

  1. Remove the front cover. Refer to Disassembly and Assembly, "Housing (front) - Remove".

    View Image

    Illustration 2g01361879

    Loosen stub shaft assembly.

    (9) Nuts

    (10) Stub shaft

  1. Remove the adjustable idler gear from stub shaft (10) . The stub shaft is held in position with five nuts (9) and one bolt. Loosen each of the five nuts and loosen the one bolt.

    View Image

    Illustration 3g01361883

    Installation of the adjustable idler assembly

    (A) Gear gauge

    (9) Nuts

    (11) Bolt

  1. Install Tooling (A) onto the engine. Refer to Illustration 3 in order to correctly position the gear gauge. Ensure that the gear gauge is seated correctly. Lightly tighten each of the nuts and the bolt in order to loosely secure the stub shaft to the engine. Once the nuts and the bolt are tightened, lightly tap the gear gauge with a rubber mallet on each side. This will ensure that the tool is properly seated. The gear gauge should be free to move in and out without any binding. Tighten the nuts and the bolt to a torque of 55 ± 10 N·m (41 ± 7 lb ft).

    View Image

    Illustration 4g01361884

    Checking backlash

    (B) Indicator assembly

    (2) Camshaft gear

    (3) Idler gear assembly

  1. Install Tooling (B) on the timing gear housing. Measure the backlash between camshaft gear (2) and idler gear (3) . When the idler gear is held stationary, the backlash between the gears is 0.216 ± 0.114 mm (0.0085 ± 0.0045 inch).
  1. If necessary, repeat step 2 through step 4 until the correct backlash is obtained.
  1. Install the front cover. Refer to Disassembly and Assembly, "Housing (Front) - Install".


Expert:  Tim replied 8 years ago.

here is the Injector adjustment...

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

Note: Determine the style of variable valve actuator that is installed on the engine. For the BXS engines, remove the variable valve actuators. For the MXS engines, it is not necessary to remove the variable valve actuators.

View Image

Illustration 1g01023138

Injector Mechanism

(1) Rocker arm

(2) Adjustment 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".
  1. 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.
  1. Turn unit injector adjustment screw (2) clockwise until the correct height is obtained.
  1. Hold the adjustment screw in this position and tighten locknut (3) to a torque of 100 ± 10 N·m (74 ± 7 lb ft).
  1. 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.
  1. Repeat Steps 3 through 4.
  1. Remove the timing bolt from the flywheel after all the unit injector adjustments have been made. Reinstall the valve mechanism cover.






Expert:  Tim replied 8 years ago.

Hello, was just wondering if this was all the information you needed


Thank you,