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MAINTENANCE
Crusader
MC-8
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9_73_~] .
MANUAL
clamps and turn tie-rod aS- required then tighten
the clamps. If the vehicle is not on gauge plates,
move it backward then forward about six feet.
9.
Recheck the toe-in to ensure that it is correct.
STEERING GEOMETRY
Steering geometry is dependent on the design of the
front end components. Field adjustments are not
possible, but a check should be made to see that
steering arms, linkage and other parts are properly
installed and are not bent and distorted. Bent or
damaged parts should be replaced. The alignment
chart includes measurements which can be made to
determine sattsfactory condition of front end parts.
MAINTENANCE
Periodic inspection of the front axle assembly
should be made to see that all bolts are tight and that
no damage and distortion has taken place. Suspension
support stud nuts, U-bolt nuts, tie-rod arm and
steering arm nuts, and stop screws should be checked
and tightened if necessary to the torque specifications
shown at the end of this section. Attention should
also be given to the condition of the steering knuckle
pins and bushings. If excessive looseness is found at
this point, the bushings and pins should be replaced.
LUBRICATION
Periodic lubrication according to the recom-
mendations in the lubrication section of this manual
should
be carried
out.
Points which
require
lubrication are the steering knuckle pins, tie-rod
ends, and drag link ends. These are provided with
grease fittings for pressure lubrication.
Refer to Section 12 (Suspension) for details of
procedures necessary to remove and install the front
axle assembly.
Steering knuckles, king pins, and bushings may be
replaced without removing the axle from the coach.
Tie-rod and drag link ends may also be replaced
without removing the axle.
If extensive overall work or straightening of the
front axle center are necessary, the axle should of
course, be removed.
CASTER
The purpose of caster angle ("N" on the chart) is to
give a trailing effect. This results in stabilized
steering and a tendency of the wheels to return to the
straight ahead position after making a turn.
Excessive caster results in hard steering around
corners. A shimmy may also develop when returning
to the straight ahead position.
Insufficient
caster
will
cause wandering and
weaving.
Caster variations may be caused by a bent axle,
tilting or distortion of side suspension supports, or
unequal tightening of the front and rear suspension
support bolts.
KING PIN INCLINATION
The purpose of king pin inclination (B on the
chart) is the same as the purpose of camber. A check
of the
king pin inclination may be made by
measurement (U and V on the chart). The use of
proper instruments in making these measurements
cannot be overemphasized.
STRAIGHTENING AXLE CENTER
The front axle center is a steel forging, heat treated
for toughness and resistance to bending and torsional
strain. If the center is bent or twisted less than ap-
proximately 5 degrees from t:'ie _original shape, it may
be straightened. However, 1t 1s recom!11ended that
this work be done only by mechantcs who are
thoroughly familiar with such operations and_ where
the proper facilities are available. Parts which are
distorted more than approximately 5 degrees from
the original shape must b~ r~p~aced, since su_ch
distortion exceeds the elastic hm1t of the matenal
causing fractures which may result in failure under
ordinary operating conditions.
CAUTION: Never apply heat to a front axle forging.
Front axle parts should be straightened cold only.
FRONT WHEEL ALIGNMENT SPECIFICATIONS
Camber (B minus A) degrees ............................... Right: Negative I /4°
::t
3/8°
........................ Left: Positive 1 /4°
t
3/8°
King Pin Inclination (D) degrees ........................................... Left: 6- I /4°
................................ Right: 6-3/4°
Toe-In
(J
minus
H) .........................................
I /16" plus or mi~u_s I /16',;
Caster Angle (N) ......................................................... Pos1t1ve 1.5
Drag Link Arm Center Ball Stud to Top of I-Beam (E) .......... 8'.'. plus or m\nus 1/8'.'.
Top of Tie Rod Below Spring Seat (F) . . . . . . . . . . . . . . . . . . . . . . .
1-1
/4
plus or mmus
1
/8,,
Tire Overhang (G) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . appr~x.
6
3,,
Wheel Track...................................................................
9. 0
Steering Arm Ball to Axle Centerline ....................... On C.L. plus or minus 1 /8"
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