Cummins ISX11.9 CM2250 – Service Manual 001-115   Idler Gear, Camshaft Rear

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 or assembly weighs greater than 23 kg [50 lb]. To reduce the possibility of serious personal injury, be sure to have assistance or use appropriate lifting equipment to lift this component or assembly.

WARNING  Support the rear of the engine using the rear support attached to the rear of the cylinder block. Failure to support the engine can cause personal injury.

• Disconnect the batteries. Refer to the OEM service manual.
• Remove the fuel pump. Refer to Procedure 005-016 in Section 5.
• Remove the starting motor. Refer to Procedure 013-020 in Section 13.
• Disconnect the crankshaft position sensor. Refer to Procedure 019-365 in Section 19.
• If equipped, remove the rear power take-off. Refer to Procedure 009-022 in Section 9.
• Support the rear of the engine.
• Remove the transmission. Refer to the OEM service manual.
• Remove the flywheel. Refer to Procedure 016-005 in Section 16.
• Remove the flywheel housing. Refer to Procedure 016-006 in Section 16.

NOTE: Place a mark anywhere on the camshaft gear and housing so that any camshaft rotation can be seen.  If the camshaft rotates while the idler gear is removed, the engine will have to be static timed.

Remove the camshaft idler gear as an assembly. Leave the snap ring on the shaft and remove the capscrew.

Disassemble the idler gear assembly. The components are listed below.

1. Capscrew
2. Snap ring
3. Front thrust bearing
4. Idler gear
5. Rear thrust bearing
6. Idler gear shaft
7. Dowel rod.

Mark or tag the individual pieces of the idler gear assembly and attach them together.

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.

Clean the parts with solvent.

Dry with compressed air.

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

Use a bristle brush to clean the oil drillings in the idler gear shaft.

Blow out the oil drillings with compressed air.

Use a straightedge to inspect the retaining capscrews for necking.

If necking is observed, do not reuse the capscrews. They must be replaced.

Inspect the idler gear for chipped, broken, or cracked teeth.

Replace the idler gear if damage is found.

Measure the inside diameter of the idler gear bushing bore.

Camshaft Idler Gear Bushing Bore Inside Diameter

Measure the outside diameter of the idler gear shaft.

Camshaft Idler Gear Shaft Outside Diameter

Visually inspect the camshaft idler gear ring dowel on the engine block as well as the locating dowel on the idler gear shaft for damage. Replace the dowels if damage is found.

Measure the thrust washer thickness in three places, 120-degrees apart.

Camshaft Idler Thrust Washer Thickness

Flex the thrust washers approximately 3 to 6 mm [1/8 to 1/4 in] and inspect the surfaces for cracks.

Assemble the ilder shaft over the locating ring dowel for the gear housing, lining up the idler shaft ring dowel with the oil feed hole in the gear housing.

Install the capscrew through the shaft and ring dowel into the block.

Tighten the capscrew.

Install the inner thrust bearing.

Lubricate the inner diameter of the idler gear with Lubriplate™ 105, or equivalent.

Install the idler gear over the shaft.

Install the outer thrust bearing on the idler shaft with the larger thrust face, facing the gear.

Install the snap ring into the groove in the idler shaft.

Check the idler gear backlash.  Refer to Procedure 001-055 in Section 1.

WARNING  This component or assembly weighs greater than 23 kg [50 lb]. To reduce the possibility of serious personal injury, be sure to have assistance or use appropriate lifting equipment to lift this component or assembly.

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.

• Install the flywheel housing. Refer to Procedure 016-006 in Section 16.
• Install the flywheel. Refer to Procedure 016-005 in Section 16.
• Install the transmission. Refer to the OEM service manual.
• If equipped, install the rear power take-off. Refer to Procedure 009-022 in Section 9.
• Connect the crankshaft position sensor. Refer to Procedure 019-365 in Section 19.
• Install the starting motor. Refer to Procedure 013-020 in Section 13.
• Install the fuel pump. Refer to Procedure 005-016 in Section 5.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine to normal operating temperature and check for leaks.