MCi Crusader II 1989 Maintenance Manual page 8

Date
Page
1-2
MC-9 MAINTENANCE MANUAL
Steering knuckles are bushed in the upper and lower pm
bosses so that they may turn fr:eel¥.about the pins. Bushings are
grooved on the inside to allow grease to flow uniformly to
high-pressure areas. Grease fittings are installed at both upper
and lower king pin bosses.
On the earlier MC-9 front axles the
tapered
steering knuckle
pins
are drawn into the axle center by tightening the nut at the
upper
end
of the
pin. On the later
MC•9s a straight
type
knuckle
pin is used. The straight
type
pin
i~
held in place by
draw keys
in
the knuckle. "
Wheel bearings. air suspension. steering and brake parts
which are mounted on the front axle are describe<;l in the appli-
cable sections of this manual.
LUBRICATION
Periodic lubrication according to the recommendations 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.
MAINTENANCE
Periodic mspection of the front axle assembly should be
made to see that all. bolts are tight and that no damage or
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 1f necessary to the torque
specifications shown at the end of this section. Attention should
also be given ·to the condition of the steering knuckle pin and
bushings. If excessive looseness is found• at this point. the
bushings and pins should be replaced.
The axle manufacturer recommends that the bronze or
"Easy Steer" king pin bushings be replaced when the range of
side-to-side tire movement reaches .030 inch or when the
bushings are worn to a maximum of .010 inch on their diameter.
NOTE: These measurements are made with
the wheel bearings tightened on the spindle.
With new bushings installed. the range of side-to-side tire
movement should not exceed .010 inch maximum. Refer to
Figure 1-2.
Looseness in the steering linkage under normal steering
toads is sufficient cause to immediately check all pivot pomts
tor wear. regardless of accumulated m!leage. Steering linkage
p,vot points should be checked each time the axle assembly ,s
lubricated. If any 1nd1cat1on of lateral movement is found. cross
tube ends should be removed for inspection. Looseness at the
steering linakge pivot points can be visually detected during
movement of the ven1cle steering wheel.
Steering knuckles. king pins. and bushings may be replaced
without removing the axle from the coach.
.010 INCH MAX.
SIDE-TO-SIDE
TIRE MOVEMENT
FRONT OF TIRE
NEW
BUSHINGS
.030 INCH MAX.
SIDE-TO-SIDE
TIRE MOVEMENT
(OR BUSHING
DIAMETER
WORN .010")
..,&.-·----
FRONT OF TIRE
WORN
BUSHINGS
Figure 1-2. Side-To-Side Tire Movements With New And
With Worn King Pin Bushings.
If extensive overall
work
or straightening of the front axle
center ,s necessary. the axle should. of course. be removed.
WARNING: Do not attempt to repair,
remove or reinstall front axle with the vehi-
cle supported by jacks only.
FRONT AXLE REMOVAL (Prior to unH 41089)
To remove the entire front axle assembly first block the rear
wheels to prevent the vehicle from rolling. Raise the front end of
the coach with jacks until the bottom of the coach body is
approximately
18"
(45 7.2 mm) from the floor. Block the body in
this position as indicated in Section 3 under Coach Jacking
Points.
CAUTION: Do not raise the body in such a
way that the entire weight of the front axle
will hang on the suspension bellows
assemblies. Damage to the bellows may
result.