TM 5-3820-241-34
replace the complete set. Determine the extent of
wear by comparison with a new vane.
(a) Inspect t h e m o t o r s h a f t n e e d l e
bearings for excessive wear or other damage.
(b) Inspect all gears for chipped teeth,
excessive wear, or other damage.
( c ) Inspect the bronze bushing in the
counter gear for excessive wear by rocking the
counter gear. Any excessive angular play will
cause rapid wear so the bushing must be replaced.
5-12. Drifter Drill, Reassembly and Installation
a. Reassembly.
(1) Coat all parts with a light film of oil
before reassembly. With the exception of press fit
bushings, all parts go together easily and will not
be forced.
(2) Reassemble the drifter drill in the reverse
of numerical sequence as illustrated in figure 5-8.
(3) When assembling the torque com-
pensator counter (fig. 5-11) apply rock drill oil on
both sides of friction plates. Tighten locknut until
springs are flattened out completely. Then, back
off locknut approximately one flat until the set
screw hole matches the flat on the gear hub.
Install setscrew using Loctite Retaining Com-
pound. Lock screw tightly and place a drop of
Loctite on both back and front of setscrew. Bend
ears of lockwasher around locknut as shown in
(4) To assemble the dual rotation unit refer
Figure 5-11. Reassembly of drill rotation unit.
to figure 5-11 and proceed as follows:
5-16