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

The ISX11.9 CM2250 uses the same flywheel housing for all engine applications.

NOTE: The flywheel housing for engines equipped with a REPTO have an additional threaded plug. 

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

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.

CAUTION  Place a wooden block, the width of the oil pan, between the floor jack and oil pan to prevent damage to the engine.

• Disconnect the batteries. Refer to the OEM service manual.
• Remove the engine crankshaft speed/position sensor. Refer to Procedure 019-365 in Section 19.
• If equipped, remove the vehicle speed sensor. Refer to the OEM service manual.
• If equipped with a wet flywheel, remove the plug in the bottom of the flywheel housing and drain the oil.
• Remove the transmission, clutch, and all related components, if equipped. Refer to the OEM service manual.
• Remove the starting motor. Refer to Procedure 013-020 in Section 13.
• Remove the flywheel (if equipped). Refer to Procedure 016-005 in Section 16.
• Remove the flexplate assembly (if equipped). Refer to Procedure 016-004 in Section 16.
• Remove any OEM attached components (mufflers, shift mechanisms, air filters, etc.) to the flywheel housing. Refer to the OEM service manual.
• Remove the rear crankshaft oil seal. Refer to Procedure 001-024 in Section 1.
• Use a floor jack or a suitable lifting fixture to support the rear of the engine.
• Remove both rear engine mounts. Refer to Procedure 016-010 in Section 16.

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.

Determine the capscrew thread design and size. Install two “t-handles” in the flywheel.

Use a hoist and lifting sling to aid in removing the flywheel housing. 

Install the lifting sling around both sides of the upper housing (1) and (2). Adjust the hoist until there is tension in the lifting sling.

Loosen, but do not remove, the flywheel housing capscrews.

Use a rubber hammer to break the seal between the flywheel housing and the rear gear housing.

Remove capscrews 3 and 4 and install two guide pins, Part Number 3376697.

Remove the remaining capscrews.

NOTE: Identify the location of the flywheel housing capscrews as they are removed. Some of the capscrews are different lengths and size, and must be installed in the same location from which they were removed.

Remove the flywheel housing.

Remove the strip seal from the groove on the rear gear houing and discard.

Remove and note the location of any threaded plugs in the flywheel housing.

Remove the rear camshaft cover plate.  Refer to Procedure 001-011 in Section 1.

Remove and discard the strip seal.

Remove the plug and o-ring from the barring gear hole.

Discard the o-ring.

WARNING  When using a steam cleaner, wear safety glasses or a face shield, as well as protective clothing. Hot steam can cause serious personal injury.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Use steam or solvent to clean the flywheel housing.

Dry with compressed air.

Inspect all surfaces for nicks, burrs, or cracks and other damage, especially in the area of the flywheel housing mounted to the cylinder block or rear gear housing.

Inspect the flywheel housing transmission/drive unit mounting surface for cracks or other damage.

Inspect for damaged threads, commonly caused by cross-threaded capscrews or installing an incorrect capscrew.

Repair or replace the housing if the capscrew holes are damaged.

Inspect the rear face of the gear housing and flywheel housing mounting surface for cleanliness and raised nicks or burrs.

Use a fine crocus cloth to remove small nicks and burrs.

Thoroughly clean the flywheel housing and gear housing mating surfaces. These surfaces must be clean and free of oil and debris.

Repair or replace the housing if the capscrew holes are damaged.

Measure the flywheel housing crankshaft bore.

Flywheel Housing Crankshaft Bore

If the flywheel housing crankshaft bore is not within specification, the flywheel housing must be replaced.

For wet flywheel housings, apply pipe sealant, Part Number 3375066, to any threaded plugs previously removed.

Install and tighten the plugs. Use the following procedure for pipe plug torque values. Refer to Procedure 017-007 in Section 17.

If equipped with REPTO, install the REPTO oil passage threaded plug.

Tighten the threaded plug.

Install the rear camshaft cover plate.  Refer to Procedure 001-011 in Section 1.

Use a new o-ring and install the plug to the barring gear hole.

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.

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.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

CAUTION  Place a wooden block, the width of the oil pan, between the floor jack and the oil pan to prevent damage to the engine.

• Connect any OEM attached components (mufflers, shift mechanisms, air filters, etc.) to the flywheel housing. Refer to the OEM instructions.
• Install both rear engine mounts. Refer to Procedure 016-010 in Section 10.
• Remove the floor jack or lifting fixture used to support the rear of the engine.
• Install the rear crankshaft oil seal. Refer to Procedure 001-024 in Section 1.
• Install the flywheel (if equipped). Refer to Procedure 016-005 in Section 16.
• Install the flexplate assembly (if equipped). Refer to Procedure 016-004 in Section 16.
• Install the starting motor. Refer to Procedure 013-020 in Section 13.
• Install the transmission, clutch, and all related components, if equipped. Refer to the OEM service manual.
• Install the wet flywheel and refill the oil, if equipped. Refer to the OEM service manual.
• Install the vehicle speed sensor, if equipped. Refer to the OEM service manual.
• Install the engine crankshaft speed/position sensor. Refer to Procedure 019-365 in Section 19.
• Connect the batteries. Refer to Procedure 013-009 in Section 13.
• Operate the engine and check for proper operation.