Cummins ISX11.9 CM2250 – Service Manual 016-006   Flywheel Housing

Install a new strip seal into the groove on the rear gear housing.

NOTE: Engines equipped with REPTO use a different strip seal than engines not equipped with REPTO. Make sure the correct strip seal is installed.

WARNING  This component weighs 23 kg [50 lb] or more. To reduce the possibility of personal injury, use a hoist or get assistance to lift this component.

NOTE: Before installing the flywheel housing, make sure any locating gear housing dowel pins are in the same position as when the flywheel housing was removed.

Install the flywheel housing over the guide pins.

Install new sealing washers behind the M12 mounting capscrews.

Install the capscrews in the same locations as when they were removed.

Remove the guide pins, and install the remaining two capscrews.

Tighten all of the capscrews.

Tighten all M16 capscrews in the sequence shown.

Tighten the M12 capscrew on the flywheel housing, using an alternate sequence between the two groups of three capscrews.

NOTE: Make sure there is a sealing washer installed behind each capscrew or an oil leak will occur.

Tighten the M10 capscrews in the sequence shown.

Read this before proceeding with the Measure section. Follow this section only if the flywheel housing (or rear gear housing for rear gear train engines) is being replaced, or if troubleshooting a vibration or alignment issue. It is not necessary to measure bore alignment or face alignment when installing the original flywheel housing, unless the gear housing dowel pins were removed or damaged during a previous repair.

CAUTION  The dial indicator tip must not enter the capscrew holes, or the gauge will be damaged

Face alignment is determined by calculating the total indicator reading (TIR).

Attach the dial indicator gauge, Part Number 3376050, to the crankshaft. Use mounting tool, Part Number ST1325, to attach the dial indicator to the crankshaft as illustrated.

NOTE: The dial indicator can be mounted by any method that holds the extension bar of the indicator rigid, so it does not sag. If the bar sags or the indicator slips, the readings obtained will not be accurate.

Position the indicator at the 12-o’clock position and zero the gauge.

NOTE: The crankshaft must be pushed toward the front of the engine to remove the crankshaft end clearance each time a position is measured.

Use the barring tool, Part Number 3163773, to slowly rotate the crankshaft.

Record the readings at the 3-o’clock (A), 6-o’clock (B), and 9-o’clock positions (C).

The values for A, B, and C can be positive or negative.

Continue to rotate the crankshaft until the indicator is at the 12-o’clock position.

Check the indicator to make sure the needle points to zero. If it does not, the readings will be incorrect and the procedure will have to be redone.

Determine the total indicator reading (TIR).

TIR is determined by calculating the difference between the highest and lowest measurement from the four locations measured.

As the example below illustrates, the TIR would be:

+ 0.08 mm – (-0.05 mm) = 0.13 mm

[+0.003 in – (-0.002 in) = 0.005 in]

The maximum allowable TIR is determined by the diameter of the flywheel housing bore. If the TIR is out of specification, replace the flywheel housing.

NOTE: For rear gear train engines, the rear gear housing may also be the cause of the TIR being out of specification.

Attach the dial indicator gauge, Part Number 3376050, to the crankshaft. Use mounting tool, Part Number ST1325, to attach the dial indicator to the crankshaft, as illustrated.

NOTE: The dial indicator can be mounted by any method that holds the extension bar of the indicator rigid, so it does not sag. If the bar sags or the indicator slips, the readings obtained will not be accurate.

Position the indicator in the 6-o’clock position and zero the gauge.

Slowly rotate the crankshaft. Record the readings obtained at the 9-o’clock, 12-o’clock, and 3-o’clock positions as A, B, and C in the concentricity work sheet.

Check zero at the 6-o’clock position. If it does not zero, the readings will be incorrect and the procedure will have to be redone.

The values for A, B, and C can be positive or negative. See the accompanying illustration to determine the correct sign when recording these values.

CAUTION  Do not force the crankshaft beyond the point where the bearing clearance has been removed. Do not pry against the flywheel housing. These actions could cause false bearing clearance readings and result in engine damage.

Rotate the crankshaft until the dial indicator is at the 12-o’clock position and zero the gauge.

Use a pry bar to raise the rear of the crankshaft to its upper limit.

Record the value as D on the concentricity work sheet. This is the vertical bearing clearance adjustment, which will always be positive.

Create a concentricity work sheet as illustrated to determine the values for the “total vertical” and “total horizontal” values.

NOTE: The values listed in the concentricity work sheet illustrated are for example only, and are listed in inches. The actual numbers measured may differ.

Input the values recorded for A, B, C, and D into the concentricity work sheet.

The total horizontal is the 9-o’clock reading (A) minus the 3-o’clock reading (C).

The total vertical is the 12-o’clock reading (B) plus the bearing clearance (D).

Example:

• 6-o’clock = reference = 0
• 9-o’clock = (A) = 0.004
• 12-o’clock = (B) = 0.003
• 3-o’clock = (C) = (-0.002)

Using the work sheet and the numbers from the example, the total horizontal value equals 0.006 and the total vertical value equals 0.005.

NOTE: Use the corresponding chart for the SAE 1, SAE 2, or SAE 3 flywheel housings being measured.

Using the illustration, mark the total horizontal value on the horizontal side of the chart and the total vertical on the vertical side of the chart.

Use a straightedge to find the intersection point of the total horizontal and total vertical values. The intersection point must fall within the shaded area for the flywheel housing concentricity to be within specification.

Using the total horizontal and total vertical values from the previous example, the intersection point falls within the shaded area. Therefore, the flywheel housing concentricity is within specification.

NOTE: Make sure to use the correct total indicator reading (TIR) specifications for the flywheel housing being measured when comparing measurements.

This chart is for a SAE 2 flywheel housing.

This chart is for a SAE 3 flywheel housing.

CAUTION  Do not remove the dowel rings located in the rear gear housing in an attempt to relocate the flywheel housing. The dowel rings are required to locate the rear gear housing to the cylinder block for proper gear alignment. Improper gear alignment will result in engine damage.

For rear gear train engines, if the bore alignment is out of specification:

1. Determine if the flywheel housing, rear gear housing, or cylinder block has recently been replaced. If any of these components have been replaced, remove and inspect/replace the component.
2. If the flywheel housing, rear gear housing, or cylinder block have not been recently replaced, remove the flywheel housing. Inspect the rear gear housing and flywheel housing mounting surfaces. If no damage is found, remove the rear gear housing and inspect the cylinder block and rear gear housing mounting surfaces.

Measure the bore and face alignment again.

If bore and face alignment does not meet the specifications, loosen the housing capscrews. Tighten the capscrews, and measure the bore and face alignment again.