TM 5-3810-300-24&P-3
1.7.4 IDLER GEAR AND BEARING ASSEMBLY
Fig. 6 - Plates for Bearing Test Fixture
rotating. Make several checks to obtain an average
reading. If the pull is within 1-1/4 lb. minimum to 6
lbs. 12 ounces maximum and does not fluctuate
more than 2 lbs. 11 ounces, the idler gear and
bearing assembly are satisfactory for use.
To check the pre-load by the second method:
Fig. 5 - Fixture for Testing Bearing Pre-Load
1. Attach the plates (two upper plates of Fig. 6) to the
To check the pre-load by the first method:
idler gear with "-13 center bolt, washers and nut as
shown in Fig. 5. Tighten the bolt to 80-90 lb-ft
1. Mount the idler gear assembly on the engine.
torque.
2. Install the center bolt and washer through the gear
2. Attach the other plate to the idler gear with
hub and thread into the cylinder block (effective with
3A-48440, 4A-96718, 6A-101509 a "-13 x 2 " bolt
replaced the "-13 x 2" bolt). Tighten the bolt to 80-
90 lb-ft torque.
3. Place steel plate (lower plate shown in Fig. 6)
against hub and bearing. Insert three 3/8"-16 bolts
through plate and thread into hub. Tighten the bolts
to 25-40 lb-ft torque.
4. Tie one end of a piece of lintless 1/8" cord around a
1/8" round piece of wood (or soft metal stock). Place
the wood between the teeth of gear, then wrap the
cord around the periphery of the gear several times.
Attach the other end of the cord to spring scale, J
8129 (Fig. 7). Maintain a straight, steady pull on the
scale, 90 to the axis of the hub, and note the pull, in
Fig. 7 - Checking Pre-Load of Idler Gear Bearing
pounds and ounces, required to start the gear
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