PS Magazine - TB 43-PS-613

PS, The Preventative Maintenance Monthly

ISSUE 613

DECEMBER 2003
PS Magazine - TB 43-PS-613 - Page 5 of 33
PS 613
DEC 03
7
M198 Towed Howitzer…
I
mproperly shimmed equilibrator adjusting screws on your M198 towed howitzer
are bad news, crewmen.
If there is a gap above the adjusting screw, the screw will be pulled up and down
as the cannon tube is elevated and depressed. A large enough gap can result in bro-
ken welds on the towers or a dished plate on the adjusting screw surface. Enough
damage means the top carriage has to be replaced.
Prevent that damage by making sure both adjusting screws on your howitzer are
properly shimmed. Here’s how:
1.
Depress the cannon tube to a near-level elevation.
2.
Using the equilibrator adjusting screw, adjust the slide to align the pointer
exactly
with the 0 on the scale.
3.
Elevate the cannon tube to a high elevation (1,000 mils minimum).
If the pointer stays aligned with
the 0 during elevation, the adjust-
ment screw is properly shimmed
and your howitzer is good to go.
If the pointer moves away from 0,
tell your mechanic. He’ll report
the problem to DS for fixing.
PS 613
DEC 03
6
M113A3 FOV…
Grease
Not Always
Needed
M
echanics, when you get in a new universal joint for an M113A3, don’t assume that
it
has
to have grease fittings.
There are two different U-joint types available. NSN 2520-00-001-3530 brings a
U-joint that has grease fittings. NSN 2520-01-413-1975 gets a U-joint that is perma-
nently lubricated. It has riveted plugs in place of the grease fittings.
if you’re one of those
mechanics or crewmen
who have been trying to
chisel or drill the
plugs loose so you can
install grease fittings,
stop it!
don’t worry!
I’ll get your
new u-joints
installed…
…soon as I
figure out how
to pry loose
those grease
plugs!
eep!
but
those u-joints
don’t
need
lube!
All you’ll
get for your
trouble is a
damaged U-joint
that
can’t
be
repaired.
ah… I’m not one
of those guys.
..
but, why shouldn’t
we… um…
those
guys
use a chisel
or drill?
Pointer moves off 0 during
elevation?
Report it!
yowza!
my
equilibriator
adjusting
screw needs
shimming!
613. 06-07 (C)
10/27/03
9:45 PM
Page 1
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