TM 5-3820-239-15
Make sure that the cylinder is
e. Inspect housings and covers for cracks,
installed correctly (when facing the
nicks and burrs on machined surfaces, and for
air port in the cylinder, the dowel
stripped and crossed threads. Remove nicks
hole is to be to the right of the air
and burrs with a fine file or handstone. Retap
port). Reverse the cylinder position
or rechase damaged threads.
if necessary.
f. Inspect gaskets (5
and 18, fig. 6-11). Re-
(6) Install rotor bearing spacer (11)
place if worn, frayed, or otherwise damaged.
(chamfered side first) on shaft of
rotor (15).
condition.
(7) Install rear ball bearing (9) (shield
g. Inspect all hardware for damaged threads.
side first) in rear end plate (4) in the
Retap or rechase all stripped and crossed
same manner as step (1).
threads. Replace if unserviceable.
(8) Stand rotor (15) with assembled
parts on the bed of an arbor press.
for scratches or score marks on the faces. Re-
Position rear end plate (10), bearing
move slight damage by rubbing the plate on a
side up, over the rotor, and using the
piece of emery cloth placed on a smooth flat
arbor press to bear only on the bear-
surface. If plates are badly scored or scratched,
ing inner race, press the rear end
replace them.
plate on until the bearing contacts
rotor bearing spacer (11).
6-20. Reassembly
(9) Install rotor bearing spring (7) over
a. Air Motor. Reassemble air motor by care-
rear ball bearing (9) so that the
fully following the step-by-step procedure giv-
spring prongs contact the bearing
en below:
outer race.
(10) Install the left-hand threaded rotor
on the bed of an arbor press. Start
lock screw securely.
front ball bearing (16) squarely into
(11) Install air port gasket (18), large
the recess in the plate. Using the
open end first, into the air inlet side
arbor press to bear only on the outer
race of the bearing, press it in until
(12) Aline the dowel holes in rear end
seated.
plate (10) and front end plate (17)
(2) Stand rotor (15) on the arbor press.
with those in cylinder (12), and insert
Using the press to bear only on the
a 1/4-inch diameter rod at least 12
inner race of front ball bearing (16),
inches long, into the dowel holes,
press the bearing and end plate onto
allowing the rod to protrude from
the rotor.
the front end plate.
(13) Insert the rod into the dowel hole of
Caution: Do not allow the end
motor housing (19) and slide the as-
plate to bind against the rotor.
sembled motor parts into the housing.
(3) If motor pinion (14) was. removed
If necessary, tap the flanged face of
from rotor (15), aline the serrations
the motor housing with a mallet to
in the pinion shank with the rotor
securely seat the motor assembly.
and press the pinion in up to the
(14) Remove the rod and install cylinder
flange.
dowel (8) to the bottom.
(4) Hold motor pinion (14) in soft vise
Note. When the dowel is completely
jaws with the rotor upright. Install
seated, the end of the dowel should be
vanes (13), making sure they fit
slightly below the back face of mar end
freely and do not project from either
plate (10).
end of the rotor.
(15) Place housing cover gasket (5) over
(6) Install cylinder (12) over rotor (15),
the boss on rear end plate (10). Seat
and against front end plate (17).
the gasket centrally.
6-23