M11 Series – Service Manual – 001-039   Idler Gear, Hydraulic 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).

SAE ‘A’ and SAE ‘B’ Removal

To remove the hydraulic drive idler gear assembly, remove:

• Mounting spacer (1)
• Rectangular seal (2)
• The three twelve-point capscrews
• Gear retainer (3)
• Rectangular seal (4)
• Front thrust bearing (5)
• Idler gear (6)
• Rear thrust bearing (7)
• Idler gear shaft (8).

NOTE: SAE “A” drives do

not use a rectangular seal (4) on the
rear surface of the gear retainer.

SAE ‘B-B’ Removal

To remove SAE B-B hydraulic drive idler gear assembly, remove:

• Mounting Spacer (1)
• Tapered Roller Bearing (2)
• Gear Drive (3)
• Tapered Roller Bearing (4)
• Shim(s) (5)
• Idler Gear Shaft (6)
• Mounting Spacer (7)
• Rectangular Seal (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 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.

NOTE: Measurements do not apply to SAE ‘B-B’ hydraulic drive idler gear. Visually inspect the inside diameter of the gear for reuse.

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.

NOTE: SAE ‘B-B’ hydraulic drive gear assembly does

not use thrust washers.

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

NOTE: SAE ‘B-B’ hydraulic drive gear assembly does

not use thrust washers.

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

SAE ‘A’ and SAE ‘B’ Install

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

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).

NOTE: When an SAE B drive is used, a special hydraulic drive idler shaft with
two oil holes is used. With the engine in the upright position, orientate the shaft so that one oil hole is at twelve- o’clock and the other at four-o’clock.

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 idler gear (6) and front thrust bearing (5).

NOTE: On SAE “B” drives, install a new rectangular seal on the rear surface
of the gear retainer (4) before installing the retainer.

Install the gear retainer (4).

Install the three retaining capscrews and tighten.

SAE ‘B-B’ Install

NOTE: Use shim(s) as necessary for proper idler gear end clearance.

Use Lubriplate™ 105, or equivalent to lubricate the roller bearings and gear.

To install SAE B-B hydraulic drive idler gear assembly, install

• Mounting Spacer (1)
• Tapered Roller Bearing (2)
• Gear Drive (3)
• Tapered Roller Bearing (4)
• Shim (s) (5)
• Idler Gear Shaft (6)
• Mounting Spacer (7)
• Rectangular Seal (8).

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.