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TRUCK SERVICE MANUAL
TM 5-4210-230-14&P-1
STEERING GEAR
48. Assemble bleed screw (20A) into housing (31), if
applicable and torque to 3.0-3.7 Nm (27-33 in.lbs.).
ADJUSTMENT OF POPPET ADJUSTING SCREWS (WITH
STEERING GEAR INSTALLED ON VEHICLE)
1.
Install a suitable pressure gage in the line between
the pump and steering valve pressure port.
2.
Actuate steering to provide full travel to wheel stops
and note pressure on gage. Adjust adjusting screw
(40) in a clockwise direction to provide a pressure at
least 2757 kPa (400 psi) below pressure noted
above. During this adjustment the oil temperature
should be approximately 54.4 deg. C (130 deg. F).
Care must be exercised to not hold pressure for
longer than 15 seconds while this adjustment is
being made, or damage to pump, from head, may
result.
3.
Repeat above procedure for other direction of
steering. During the above procedure, observe for
any tendency of the gear to self steer or motorize. If
self steering does occur, check steering column, slip
joint(s) and universal joint(s) for binding or excessive
friction. If no problem is found in these areas, the
gear should be checked as follows:
A. Is upper thrust bearing package (items 11 (2
pcs) and 12) properly installed? If the gear has
been assembled with these components out of
position they probably will be damaged and
should be replaced.
B. Is valve sleeve (15) "sticky" on worm shaft
(17)? These two parts are fitted very closely
and a nick or burr on either part can cause the
valve assembly to be sticky. Minor damage
can be corrected by polishing with crocus
cloth. If major damage is evident, the valve
sleeve (15), drive ring (16) and worm shaft
(17) should be replaced.
C. If (A) and (B) above do not stop the tendency
to self steer, the worm shaft (17) and valve
assembly should be replaced.
ADJUSTMENTS & REPAIRS WITH STEERING GEAR ON
VEHICLE
Removal of the steering gear from most vehicles is
difficult and time consuming. It is suggested that after
becoming proficient in servicing
the gear on a bench as described in this manual,
consideration be given to performing adjustment and minor
repairs without removing the gear from the chassis. On some
vehicles access to the gear may be so restricted that it must
be removed for service.
1. Adjustments: Remove input coupling and pitman arm
or drag link. Leave plumbing connected in normal
manner.
Engine
should
be
running
while
adjustments are being made.
A. Adjust sector shaft.
B. Worm Preload Adjustment. Loosen jam nut
(38), tighten adjusting screw (39) to 2.8-3.4
Nm (25-30 in.lbs.) and retighten the jam nut
to 95-109 Nm (70-80 ft.lbs.) while holding the
adjusting screw so that it does not rotate when
the jam nut is tightened. Purpose of this
adjustment is to put a light preload on the
worm thrust bearing package items (11 and
12). After the adjustment has been made,
there should be no perceptible in and out
movement of the input shaft when it is
oscilated from right turn to left turn and back.
The input shaft should rotate smoothly and
without binding thru full travel of the gear with
a maximum torque of 3.7 Nm (33 in.lbs.).
2. Repairs
A. On many installations the trunnion cover (26)
can be removed from the gear allowing
service of the output shaft seal package (23
and 24) and the trunnion cover seal (25).
Remove the pitman arm and clean gear in
area of trunnion cover so dirt will not get into
gear
while
trunnion
cover
is
removed.
Remove dirt seal (27), clean dirt and paint
from shaft. Remove trunnion cover and shaft
seal package. Clean portion of shaft now
exposed using fine emery paper if necessary.
Cover shaft serrations with cellophane tape
and reassemble using new shaft seal package
(23 and 24), seal (25) and dirt seal (27). Add
fluid
to
reservoir
and
bleed
system
if
necessary.
B. If the input shaft area is accessible, the input
shaft seal assembly, items (7) and (8) can be
replaced with a minimum of effort by the
following procedure. Remove the input
coupling and clean the area of the gear
around the input shaft. Remove supply and
return hoses from gear and plug hoses.
Remove fittings
CTS-2717 Page 15
PRINTED IN UNITED STATES OF AMERICA
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