M11 Series – Service Manual – 001-040   Idler Gear, Water Pump

Remove the gear cover.

Refer to Procedure 001-031.

Three idler gear assemblies are used:

• Water pump idler gear (1)
• Camshaft idler gear (2)
• Hydraulic pump idler gear (3).

NOTE: The water pump

must be removed before the water pump idler
gear (1) can be removed.

Refer to Procedure 008-062.

To remove the water pump idler gear assembly, remove:

• The three capscrews
• Cover plate (4)
• Front thrust bearing (5)
• Idler gear (6)
• Rear thrust bearing (7)
• Idler gear shaft (8).

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

Clean the parts with solvent. Dry with compressed air.

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

Blow out the oil drilling 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.

Measure the outside diameter of the idler gear shaft.

Measure the outside diameter of the ring dowel.

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

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

CAUTION  The grooved side of the rear thrust bearing must be facing toward the gear to prevent damage to the gear and engine during engine operation.

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

Install the rear thrust bearing.

Install the idler gear without the shaft.

Align the inside diameter of the rear thrust bearing with the inside
diameter of the idler gear.

The shaft

must pass through the gear and pilot into the
rear thrust bearing. After installation, the shaft

must protrude

only slightly more than the thickness of the front thrust bearing.
Excessive shaft protrusion beyond the thickness of the front thrust bearing
indicates the shaft is

not properly piloted into the rear thrust bearing.

Install the shaft into the gear bore.

CAUTION  The grooved side of the front thrust bearing must be facing toward the gear to prevent damage to the gear and engine during engine operation.

Install the front thrust bearing.

Install the gear retainer.

Install the capscrews and tighten.

Install the water pump.

Refer to Procedure 008-062.

The following idler gear end clearance and backlash checks apply to
all three idler gears. The same

MINIMUM and

MAXIMUM values apply, also.

Use a dial indicator gauge with a magnetic base to measure the idler
gear end clearance.

Place the contact tip of the gauge against the face of the idler gear.

Use a dial indicator gauge with a magnetic base to measure the idler
gear backlash.

Place the contact tip of the gauge against a tooth on the idler gear.

NOTE: Do

not allow the mating gears to move while measuring the backlash.

Install the gear cover.

Refer to Procedure 001-031.

Operate the engine to normal operating temperature and check for leaks.