Idler Gear

TM 10-3930-634-34

screws (15). Tighten screws to 30-35 lb-ft torque.

(9) Tighten pulley nuts (1) and gear nuts (9) to

300-325 lb-ft torque.

(10) Attach the gear nut retainer plates (8) to the

gears with bolts (6) and tighten the bolts to 35-39 lb-

ft. torque.

(11) Check the clearance between the thrust wash-

er and the gear on both shafts. The clearance should be

0.008 to 0.015 inch, or a maximum of 0.019 inch with

used parts.

( 1 2 ) Check the backlash between the mating

gears. The backlash should be 0.003 to 0.005 inch and

should not exceed 0.007 inch for used parts.

(13) Install the hydraulic pump adapter (7) on the

balance shaft gear.

(14) Install flywheel and flywheel housing (paras

3-32 and 3-33).

(15) Install cylinder head (para 3-25).

(16) Install engine (para 2-5) and accessory parts

and assemblies.

( 1 7 ) Fill the cooling system (TM 10-3930-

634-12).

3-36. Idler Gear

as an assembly. Separate the thrust washer from the

a. General. The engine idler gear and bearing assem-

hub.

bly, located at the flywheel end of the engine, meshes

c. Disassembly. Press sleeve bearing from idler

with the camshaft and crankshaft gears and rotates on

gear.

a stationary hub. The hub is secured directly to the

d. Cleaning. Clean all parts with cleaning solvent

cylinder block by a capscrew which passes through the

P-D-680 and dry thoroughly with compressed air.

hub and three capscrews which pass through the fly-

e. Inspection and Repair.

wheel housing, hub and end plate. Two timing marks

(1) Inspect the gear teeth and bearing for scoring,

are stamped on the idler gear diametrically opposite

pitting and wear. Replace gear and bearing as re-

each other.

quired.

b. Removal.

(2) Inspect thrust washers for wear. Replace as

(1) Remove the engine (para 2-5).

necessary.

(2) Remove the flywheel housing (para 3-33).

NOTE

(3) Remove the rear idler thrust washer (4, fig.

The standard inside diameter of the idler

3-126).

gear bearing is 2.186 inches and the standard

(4) Slide the idler gear assembly (6) off the hub (5).

outside diameter of the hub is 2.1825 to

(5) Remove screw (3) which secures the hub to the

2.1835 inches. Maximum wear limit 0.007

cylinder block.

inch. The standard side clearance between

(6) Remove the front thrust washer (7) and hub (5)

thrust washer and idler gear is 0.006 to 0.013

3-80