M11 Series – Service Manual – 001-036   Idler Gear, Camshaft

Remove the gear cover.

Refer to Procedure 001-031.

Before removing the idler gear, use the accessory driveshaft to rotate
the crankshaft until the timing marks on the crankshaft gear (1), camshaft
gear (2), and accessory drive gear (3) are completely engaged in the camshaft
idler gear.

NOTE: Due to the camshaft idler gear having more gear teeth than the crankshaft
gear, the camshaft idler gear timing marks will

not align with the crankshaft, camshaft, and accessory drive gears timing marks on
every engine revolution.

Three idler gear assemblies are used:

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

To remove the camshaft 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)
• Wear plate (9).

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 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.

Measure the outside diameter of the idler gear shaft.

Measure the outside diameter of the camshaft idler shaft 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.

When installing the camshaft idler gear (1), make certain the timing
mark “0”on the crankshaft gear (2), timing mark “X”
on the camshaft gear (3), and timing mark “V” on the accessory drive gear (4) are aligned as shown.

The marks on the idler gears should match the same mark on each of the other gears.

NOTE: Only the camshaft idler gear has a wear plate.

Use Lubriplate™ 105, or equivalent, to lubricate the wear plate, thrust bearing, and idler gear.

Install the camshaft idler gear wear plate (9).

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.

Install the idler gear shaft (8) and rear thrust bearing (7).

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.

Align the timing marks and install the idler gear (6), front thrust
bearing (5), and gear retainer (4).

Install the retaining capscrews and tighten.

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.