TM 5-3810-300-24-&P-3
1.7
Engine Balance
If the thrust surface (side facing the camshaft or balance
shaft thrust washers) of the balance weight hub is
damaged, it will be necessary to install a new balance
weight.
The clearance between a balance weight bushing and
the balance weight hub is from .0005 " to .0035 "with new
parts and .006 " with used parts. The clearance between
the weight and the hub should be from .010" to .023".
Assemble Spring-Loaded Balance Weight
1. If the old bushing was removed from the balance
weight, press a new split bushing into place until the
Fig. 3 - Loosening Nut on Camshaft or
edge of the bushing is flush with the shoulder on the
Balance Shaft
drilled (balancing holes) side of the weight.
Disassemble Spring-Loaded Balance Weight
2. Select suitable springs (17 per pack) to make four
packs, each .251" .008" thick. Each spring is .015 " to
1. Remove the cotter pin from the nut (Fig. 5).
.016" thick. Measure the pack thickness while the
springs are tightly clamped together in a vise or arbor
2. Remove the bolt and the retainer.
press.
3. Separate the balance weight from the hub.
CAUTION: Wash each spring in the packs
thoroughly and dry it with compressed air
4. Push the springs and spacer from the balance
before taking the above measurements.
weight.
3. Lay the weight, machined face down, flat on a clean
5. If the bushing is badly worn, press it out of the
work bench.
weight.
4. Dip the spring pack in lubricating oil to completely
coat all the springs.
5. Arrange one spring pack on either side of the
balance weight spring cavity.
6. Place the spring spacer on the blade of a screw
Fig. 4 - Removing Balance Weight Assemblies
Inspection
Fig. 5 - Details of Spring-Loaded Type Balance
Weight and Hub Assy.
Clean all of the parts thoroughly with fuel oil and dry
them with compressed air.
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