PS Magazine - TB 43-PS-634
PS, The Preventative Maintenance Monthly
ISSUE 634
SEPTEMBER 2005
PS 634
SEP 05
9
M109A6
Paladin…
Got the SHAKES
PS 634
SEP 05
8
M113-Series FOV…
Keep Prop Shaft Bolts Tight
O
ne of the most important things you crewmen and mechanics can do is check for
loose or missing propeller shaft and U-joint bolts on M113 carriers.
If the shaft comes loose, it flails around, damaging the vehicle. If it crashes
through the floorboard, the shaft could injure or kill the driver.
Spotting a missing bolt is simple enough, but how do you check for a loose one?
That’s where you mechanics come in. When you pull semiannual PMCS, torque
all the bolts. Then make alignment marks on the bolt heads and prop shaft or U-joint
yoke. Mark them with a scribe or awl.
That makes it easy for crew-
men to double-check them dur-
ing PMCS. If the marks don’t
line up, the bolt has loosened.
Of course, the best solution
is to keep the bolts from com-
ing loose in the first place. That
means torquing the bolts right.
After torquing the bolts the
first time, drive the vehicle for-
ward about 100 feet and then
back. Re-check the torque and
tighten if necessary. The initial
stress of operation sometimes
loosens the bolts.
now hold
on while I
mark your
prop shaft
and u-joint
bolts!
Mark line across bolt
and shaft hardware
If the backlash is out of tolerance, they’ll
remove the center bottom cover and add a
shim between the backlash gear and the gas-
ket as shown on Page 13-22 of the -34-2 TM.
If the shim
doesn’t bring
the gears with-
in tolerance,
the traversing
mechanism
will have to be
disassembled
to
set
the
backlash gear.
Have your mechanic notify
DS/GS maintenance about the
problem. They’ll determine if the
gear box has the correct backlash
by measuring the traversing output
gears as shown on Page 13-31 of
TM 9-2350-314-34-2.
if you’re having
oscillation problems
on your Paladin when
using the automatic fire
control system (AFCS)…
…the cause may
be
incorrect
backlash
adjustment
of
the traversing
gear box.
Measuring between output
gears will determine backlash
Adding shim
could fix
vibration
problem
K-k-can't
suh-somebody
d-do suh-some-
thing a-about
the-these vuh-
vibration puh-
problems?
open
wide!
4.600 ±
.005
9.200 ± .010
634.08-09(C).qxd
7/29/05
11:24 AM
Page 1
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