Cummins ISX11.9 CM2250 – Service Manual 001-039   Idler Gear, Hydraulic Pump

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.

• Disconnect the batteries. Refer to the OEM service manual.
• Remove the cooling fan. Refer to Procedure 008-040 in Section 8.
• Remove the gear cover. Refer to Procedure 001-031 in Section 1.

To remove the hydraulic drive idler gear assembly, remove the following:

• The four capscrews
• Idler gear shaft
• Front thrust bearing
• Idler gear
• Rear thrust bearing.

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.

Measure the inside diameter of the idler gear bushing bore with the bushing installed.

Hydraulic Drive Idler Gear Bushing Bore Inside Diameter

Measure the outside diameter of the idler gear shaft.

Hydraulic Drive Idler Gear Shaft Outside Diameter

Inspect the idler shaft ring dowel.

Verify that the ring dowel is not damaged or sheared.

If it is damaged or sheared, replace the ring dowel.

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

Hydraulic Drive 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.

Use lubricant such as Lubriplate™ 105, or equivalent, to lubricate the thrust bearings and idler gear shaft.

Assemble the thrust bearings and idler gear onto the idler gear shaft in the following order:

• Front thrust bearing
• Idler gear
• Rear thrust bearing.

NOTE: When installing the shaft and gear assembly, make sure that the rear thrust bearing does not fall off of the idler shaft and become pinched between the shaft and the gear housing. Gear train damage can occur if the assembly or rear thrust is not properly installed.

Install the assembly onto the gear housing.

Install the retaining capscrews finger tight.

Tighten the three larger (M12) capscrews, beginning with the center capscrew.

Tighten the smaller (M10) capscrew.

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

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 front gear cover. Refer to Procedure 001-031 in Section 1.
• Install the cooling fan. Refer to Procedure 008-040 in Section 8.
• Connect the batteries. Refer to the OEM service manual.
• Operate the engine to normal operating temperature and check for leaks.