MCi Crusader II 1989 Maintenance Manual page 17

Date
1-1-89
·Page
MC-9 MAINTENANCE MANUAL
3. Shim the knuckle and axle assembly. Shims are positi-
oned between the upper axle center face and the upper
kn_uckle yoke. See figure 1-22. Shims are used to limit the
vertical movement of the knuckle with respect to the axle center
and king pin. Some clearance in this area is required, however,
to allow grease to purge from the upper bushing area. Carefully
inspect shims, new or used, to be sure none are kinked, bent or
torn. Discard any that are damaged. Select a quantity.of shims
to obtain as little vertical end play as possible. Lift the knuckle in
position and slide the shim pack between the axle center boss
and the knuckle upper yoke.
Figure 1-22. Shimming Axle And Knuckle.
Alignment of the king pin hole in the knuckle and axle
center is now required for king pin installation. While looking
dowri through the king pin hole, shift the knuckle to align it with
the axle center. Now align the shims to be flush with the axle
center around the entire circumference of the king pin hole. The·
shim alignment can only be done through the upper bushing.
Any protrusion of any portion of the shim will prevent the king
pin from passing through and result in a damaged shim.
NOTE: Shims are delicate and sharp.
Extreme caution should be exercise~ while
aligning shims so as not to cut fingers or
bend the inside diameter of the shims.
Damage to the shims during this entire
procedure requires disassembly and replace-
ment of the damaged parts.
4A To install the straight type king pin:
a. Smear clear chassis grease on the bottom half of the
king pin and insert it slowly into the top of the knuckle. King pins
are marked with the Rockwell logo, part number and the word
1p" on the top end of the pin. Rotate the pin to align the draw
ndY
slots with the draw key notes in the axle. Slowly push the pin
through the bushing, seal and shim pack. The pin should slide
through the shim pack freely. Any resistance greater than a
hand push inqicates misalignment Remove the pin and realign
the components. After the pin is inserted through the shim pack,
a brass hammer may be used to assist in instaHation. Care must
be taken not to dislodge the lower grease seal as the king pin
enters the lower knuckle yoke.
b. Center the king pin in the knuckle to equalize the
distance from the top and bottom surfaces. For knuckles with a
bottom welsh plug arrangement increase the bottom gap to
allow for assembly of the welsh plug and snap ring.
c. lightly tap the draw keys into position, flat side toward
king pin: do not firmly seat them until after the end play mea-
surement. Install the lower draw key from the front side and the
upper draw key from the rear. Assemble so the wedged ends of
the two keys contact the king pin and torque to restrict pin from
moving while the end play is measured. The p·rocedures for end
play measurement and for seating the draw keys will be found
later in this section.
NOTE: Never install both draw keys from
the same side.
4B. To install the tapered type king pin:
a. Smear chassis grease on the tapered section of the
pin and insert the pin from the bottom of the knuckle.
b. Smear chassis grease on the inside and outside of the
Ising pin sleeve and insert it into the upper bushing bore over the
king pin.
c. Install king pin nut. and torque only enough to seat the
king pin for end play measurement.
d. Measure end play according to the procedure which
is given later in this section and adjust if necessary.
e. Torque nut to 350-390 ft. lbs. (475-529 Nm) and install
cotter key. If the cotter hole does not align with the nut castella-
tion. advance the nut. Do not back the nut off.
5. Measurement of knuckle end play:
NOTE: A procedure for measuring end play
with axle installed on coach and with wheels
and tires installed can be found later in this
section.
NOTE: The use of shim gauges (feeler
gauges) for measurement of clearance toler-
ances on steering knuckles is not recom-
mended. These will not give an accurate
reading of end play. Use only a dial indica-
tor.
NOTE: End play is the free movement of the
steering knuckle up and down along the
axis of the king pin. Some end play is
required to prevent binding of the knuckle
while turning and to provide a passage for
grease to purge during bushing lubrica-
tion. Excessive end play can cause inter-
ference between the king pin and end caps
or retainers.