MCi 102D Series User manual

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
1BĆ1 Page
August 2000 Date
SECTION 1B
FRONT AXLE 16,000 LBS GA R
CONTENTS OF THIS SECTION
SUBJECT PAGE
General Description 1BĆ1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Components 1BĆ1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 1BĆ3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication 1BĆ20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 1BĆ23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speci ications 1BĆ27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fastener Torque Chart 1BĆ28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Tools 1BĆ30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION
The ront and trailing axle assemblies are drop center
cast or orged beam design with orged steel knuckle pin
ends (Figure 1). Knuckle pin ends are integral parts o the
axle center beam.
Steering knuckles have grease ittings in both knuckle
pin bosses or lubrication o the knuckle bushings. The
bushings are o the Easy Steer" type. Covers and plugs
prevent dust and moisture rom entering bushings and
serve as seals.
Identification
The axle model number identi ication plate is on the
axle center. Use the model number to order the correct
parts (Figure 2).
COMPONENTS
Axle Beam
ARNING
Do not attempt to straighten the axle. Any
manipulation or straightening of the axle could
severely reduce load rating and driveability.
The axle beam is cast or orged. The other axle
components assemble to this part.
Tie rod assembly
The tie rod assembly attaches to the tie rod arm, and to
the axle through the steering arm and knuckles. It
maintains the correct steering geometry. The tie rod
assembly has an adjustable center section and sealed
replaceable ball joint ends.
Knuckle ends
Steering knuckles are attached to the axle ends with
straight king pins and are retained by a set o draw keys.
Knuckles are itted with special king pin bushings. King
pin bushing covers, spacers and seals prevent dust and
moisture rom entering the bushings.
Stop screws installed on each knuckle assembly limit
the wheels' turning angle. Knuckles mount all steering
and wheel end components: tie rod arms, brakes and
wheel bearings and hubs).

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
1BĆ2 Page
August 2000 Date
Figure 1. Front Axle Assembly (16,000 lbs.)
Tie Rod
Tie Rod Arm
Tie Rod Arm
Steering Arm
King Pin
Axle
Q Plus Cam Brake
(Refer to Sect. 4C1)
Brake Drum
Grease Fitting
Grease Fitting
Shims
Bearing
Bushing
Bushing
Steering Knuckle
Threaded King Pin Cap
Threaded King Pin Cap

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
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August 2000 Date
FIGURE 2. Axle identification
MAINTENANCE
TIE ROD INSPECTION
Proper tie rod end inspection and replacement is an
important part o maintaining proper vehicle alignment.
Replacement o worn tie rod end will prevent premature
wear o other steering and suspension components and
will help to ensure smooth, precise steering and control.
Adhere to the ollowing procedure when per orming
regular tie rod end inspections:
Note: Tie rod end inspections should always be
performed prior to lubrication. If the inspection is
performed after lubrication, there may be a false
indication that the tie rod end is fully operative.
ă1.ăPark the vehicle with the wheels in the straight
ahead" position, then turn the vehicle o .
ă2.ăPlace blocks in ront o and behind the ront and
rear tires to prevent the vehicle rom moving.
ă3.ăTo inspect the tie rod end, care ully remove all dirt
and grease rom the seal o the tie rod end. Examine the
seal or any indication o damage such as slits, tears, etc.
I the seal utilizes a retention ring on the socket, inspect
the ring or damage.
Note: If the seal is damaged or the ring is missing,
replace the tie rod end as soon as possible.
ă4.ăI the seal and ring are acceptable, try to move the
tie rod cross tube by hand (Figure 3). I movement or
looseness is detected, set up a dial indicator, (as shown in
Figures 4 and 5).
Figure 3
CAUTION
Do not use a pry bar or other mechanical
method on the steering linkage, this could result
in damage to the tie rod end and/or create a false
indication of wear.
ă5.ăThere are two separate methods that can be used
to check the degree o movement in the tie rod end:
Figure 4
a. To check axial (up and down) movement, set
the dial indicator so that the base o the indicator is on the
tie rod arm. Then, place the tip o the indicator on the
bottom o the tie rod end at the area that it is most
lat.(Figure 4)

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
1BĆ4 Page
August 2000 Date
Figure 5
b. To check radial (back and orth) movement, set
the dial indicator so that the base o the indicator is on the
tie rod arm. Then, place the tip o the indicator on the
socket o the tie rod end. Be sure to position the dial
indicator so that it is line with the direction o movement.
(Figure 5)
ă6.ăSet the dial indicator to 0" (zero).
ă7.ăMove the cross tube assembly up and down or
back and orth, depending on which direction you are
checking or looseness. I the indicator reading is 0.060"
or more, replace the tie rod end immediately. I the
indicator reading is above 0.030", it should be replaced at
the next service interval.
CAUTION
Do not remove the tie rod end from the tie rod
arm to check for ball stud rotating torque. This
may damage the seal if a removal tool is used.
Additionally, the tie rod end seal can cause false
indications of internal torque.
ă8.ăRepeat steps three (3) through seven (7) or the
other tie rod end.
Note: hen one tie rod end requires replacement,
it is recommended to replace both to allow for even
wear on both sides of the vehicle.
REMOVAL AND DISASSEMBLY
Tie rod, tie rod arms and tie rod ends
ARNING
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
ARNING
Support the vehicle with safety stands. Do not
work under a vehicle supported only with jacks;
jacks can slip or fall over and cause serious
personal injury or death.
ă1.ăMake sure the vehicle is on a level sur ace.
ă2.ăSet the park brake.
ă3.ăPlace blocks under the wheels not being serviced
to prevent the vehicle rom moving.
ă4.ăRaise the vehicle so that the wheels to be serviced
are o the ground. Support the vehicle with sa ety stands.
ă5.ăRemove the cotter pins that asten each tie rod ball
joint to the tie rod arms (Figure 6).
Figure 6.ăTie rod end and arm
ă6.ăDisconnect the tie rod assembly rom the tie rod
arm. You might have to use a removal tool to separate the
tie rod ball joint rom the tie rod arm.
ă7.ăRemove the cotter pin and nut that asten the tie
rod arms in the knuckle.

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
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August 2000 Date
ă8.ăRemove the tie rod arms rom the knuckle. You
may have to tap on the end o the arm with a leather or
plastic mallet to separate the arm rom the knuckle.
Remove the key rom the tie rod arm.
FIGURE 7. Removing rod ends
ă9.ăI necessary, remove the tie rod ends rom the tie
rod according to the ollowing procedure:
a. Mark the position where each tie rod end is
installed in the tie rod (Figure 7). (The position o tie rod
ends determines toeĆin).
b. Remove the bolts and nuts rom the clamp on
the tie rod.
c. Remove the tie rod ends rom the tie rod.
NOTE: It is imperative to per orm a ront end alignment
to reset the toeĆin a ter tie rod ends are replaced (Re er
to Sect. 2C Alignment Procedure").
Removing the knuckle
A. Preparation
ă1.ăSet the park brake.
ă2.ăBlock the axle and coach body.
ă3.ăRemove the air rom the brake system and
disconnect the air lines rom the brakes.
ă4.ăRemove the wheel and tire assembly. (See the
Operator's manual or this procedure).
B. Hub removal
ă1.ăRemove the brake drum.
ă2.ăRemove the hub (Figure 8).
FIGURE 8. Removing cap and gasket
CAUTION
hen tightening or loosening the adjusting nuts
for the wheel bearing, always use the
correctĆsized socket, to avoid damaging the
adjusting nut.
ă3.ăBend the lock washer tabs o the jam nut and
remove the jam nut, jam nut lock washer, pierced lock
ring and adjusting nut rom the knuckle Figure 8).
ă4.ăRemove the air rom the brake system and
disconnect the air lines rom the brake chambers.
ă5.ăRemove the caliper rom the torque plate per the
manu acturer's procedure.
ă6.ăRemove the outer wheel bearing cone rom the
hub.
ă7.ăRemove the hub.
C. Knuckle removal
ă1.ăRemove the torque plate rom the knuckle.
ă2.ăRemove the tie rod arms and steer arm rom the
knuckle per the previous procedure in this manual.
ă3.ăUnscrew the king pin caps rom the top and
bottom o the knuckle.
ă4.ăRemove the threaded draw keys rom the beam,
according to the ollowing procedure:
ARNING
Do not hit steel parts with a steel hammer. The
parts can break and cause serious personal
injury.

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
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August 2000 Date
CAUTION
Apply force directly to the bottom of the nut and
the end of the key. Otherwise, the draw key will
be damaged.
FIGURE 9. Loosening the draw key
a. Loosen the lock nut and move the lock nut end
to the the end o the threads. Make sure the top o the lock
nut is even with the end o the draw key.
b. Use a brass dri t and hammer to hit the end o
the nut to loosen the draw key (Figure 9).
c. Remove the nut and draw key rom the beam.
CAUTION
If you are not replacing the bushings, do the
following to prevent damage to the bushings
while removing the king pins:
1. Remove any flaring on the drift that may touch
the king pin.
2. rap tape to a thickness of 0.0625 inch (1.5
mm) on the end of the drift.
ARNING
Obey all the press manufacturer's warnings and
cautions regarding the press operation, to avoid
serious personal injury and possible
component damage.
ă5.ăUse a brass dri t and hammer (Figure 10) to
remove the king pins rom the knuckle. I the king pin is
di icult to remove, use a hydraulic king pin remover. (See
the Service Tools subsection at the end o this document).
Figure 10.ăKing Pin Removal
ă6.ăRemove the knuckle rom the axle center beam.
ă7.ăRemove the shims, thrust bearing and seal rom
the knuckle (Figure 11).
FIGURE 11. Removing thrust bearing
ă8.ăI the knuckle bushings are damaged, remove the
bushings according to the ollowing procedure:
a. Remove and discard the upper and lower king
pin seals (Figure 12).

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
1BĆ7 Page
August 2000 Date
FIGURE 12. Removing king pin seals
b. Make a tool to remove the bushings. See
Service Tools" later in this section or the tool
dimensions.
c. Put the knuckle on the press.
NOTE: Use a press with a 5 ton (4545 kg) capacity,
and make sure the knuckle does not move when the
bushings are removed.
d. Install the tool in the upper king pin bushing.
e. Press the top bushing rom the knuckle (Figure
13).
FIGURE 13. Bushing removal
. Install the tool in the lower king pin bushing.
g. Press the bottom bushing rom the knuckle
(Figure 13).
REPAIRING PARTS
ARNING
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
Repairing or reconditioning ront and trailing axle parts
is prohibited. The axle manu acturer recommends
replacing damaged or outĆo Ć speci ication components.
All major components are heatĆtreated and tempered.
The components cannot be bent, welded, heated or
repaired in any way without reducing the strength or li e o
the component.
The ollowing operations are prohibited on ront axle
components:
ă1.ăWelding o or to steering arms, tie rod arms,
knuckles, king pins, axle centers, tie rod assemblies,
hubs, drums, or brakes.
ă2.ăHot or cold bending o knuckles, steering arms, tie
rod arms, ball studs, axle centers or tie rod assemblies.
ă3.ăDrilling out o holes in the axle center beam or
knuckle pins.
ă4.ăDrilling out o draw key holes in the axle center
beam.
ă5.ăSpray welding o bearing diameters on knuckles
or in machined bores.
ă6.ăMilling or machining o any component.
ARNING
If you use cleaning solvents, hot solution tanks
or alkaline solutions incorrectly, injury can
occur. To prevent injury, follow the
manufacturer's instructions. DO NOT use
gasoline to clean parts; gasoline can explode.
Cleaning ground or polished parts
Use cleaning solvent to clean ground or polished parts
and sur aces. Kerosene and diesel uel can be used or
this purpose. DO NOT use gasoline.
CAUTION
DO NOT clean ground or polished parts in a hot
solution tank or with water, steam, or alkaline
solutions. These solutions will cause the parts
to corrode.
Cleaning rough parts
Rough parts can be cleaned with the ground or
polished parts. Rough parts can also be cleaned in hot

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
1BĆ8 Page
August 2000 Date
solution tanks with a weak alkaline solution. The parts
must stay in the hot solution tanks until they are
completely cleaned and heated.
Drying cleaned parts
Parts must be dried immediately a ter cleaning. Dry the
parts with clean paper or rags, or with compressed air. Do
not dry bearings by spinning them with compressed air.
Preventing corrosion on cleaned parts
Apply light oil to cleaned and dried parts that are not
damaged and are to be immediately assembled. DO NOT
apply oil to brake linings.
I the parts are to be stored, apply a good corrosion
preventative to all sur aces. DO NOT apply this material to
brake linings.
Store the parts in special paper or another material that
prevents corrosion.
NOTE: make sure all tapered parts are clean and dry,
with no lubricant or corrosion preventative applied to
mating sur aces.
INSPECTING PARTS
Care ully inspect any disassembled parts be ore
reusing them. Re er to the ollowing guidelines:
ă1.ăInspect and replace any parts that are worn,
cracked, or damaged. Check or cracks using dye
penetrant, magnetic lux, or lourescent particle testing
methods.
ă2.ăMeasure the king pin bushing inside diameter
using a micrometer and telescoping gauge or taking
measurements (Figure 14).
FIGURE 14. Bushing measurement
I the average inside diameter measurement is greater
than the king pin bushing maximum inner diameter in
Table 1 below, install new bushings.
ă3.ăA ter removing a worn bushing, measure the
knuckle bore inside diameter in two locations. Always use
a micrometer and telescoping gauge when taking
knuckle bore measurements. Some rounding o the top
and bottom bore edges is acceptable.
Measure the bore in our positions and at two
locations. The two locations must be 90° opposed to
each other. I the average measurement is greater than
the knuckle bore maximum diameter speci ication in
Table 1, replace the knuckle (Figure 15).

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
1BĆ9 Page
August 2000 Date
Table 1
Axle ear Limit Specifications
Knuckle bore: maximum
diameter inches (mm)
Beam bore: maximum
diameter inches (mm)
Knuckle bushing bore: maximum
diameter inches (mm)
1.922 (48.818) 1.7980 (45.6692) 1.796 (45.618)
FIGURE 15. Knuckle measurement
Follow this procedure or both the upper and lower
knuckle bores. I either bore's diameter exceeds the limits
in Table 1, remove and replace the knuckle.
ă4.ăMeasure the inner bore diameter o the axle beam.
Rounding at the top and bottom o the beam is
acceptable.
Measure the axle beam bore at our positions, and at
two speci ic locations: 0.5 inch (12.7 mm) below the top o
the bore, and 0.5 inch (12.7 mm) above the bottom o the
bore (Figure 16).
FIGURE 16. Axle beam measurement
I the average measurement is greater than the axle
beam bore maximum diameter shown in Table 1 below,
the axle beam requires replacement.
ă5.ăInspect the taper on the tie rod arm or wear or
damage.
ă6.ăInspect the hole or taper in the knuckle. I the hole
is worn or damaged, replace the knuckle and arm. I only
the taper on the arm is damaged, replace the arm.
ă7.ăI the king pin has worn through the bushing and
into the knuckle, replace the knuckle.
NOTE: I any part o the linkage is loose, check all the
pivot points. Check the pivot points when the linkage is
lubricated.
ă8.ăMake sure all pivot points in the steering linkage
are tight.
ă9.ăInspect the thrust bearing and seal or wear or
damage. Replace parts that are worn or damaged.
Tie rods and tie rod ends
ă1.ăInspect the tie rod or wear and damage. Replace
the tube it i it is worn or damaged.
CAUTION
DO NOT repair tie rods.
ă2.ăInspect the tie rod end or wear and damage.
Replace it i it is worn or damaged. For more details, see
the troubleshooting subsection.
ă3.ăI a seal is damaged on tie rod ends with a grease
itting, replace only the seal. I the tie rod end does not
have a itting, replace the complete tie rod end.
heel bearings
ă1.ăInspect the wheel bearings when the knuckle is
inspected or repaired.
ă2.ăRemove all lubricant rom the bearings, knuckle,
hub, and hub cap.
ă3.ăInspect the cup, the cone and the rollers and cage
o all bearings. I any o the ollowing conditions exist,
replace the bearing:

102D SERIES MAINTENANCE MANUAL
01-FRONT AXLE
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August 2000 Date
FIGURE 17. ear indicators
a. The center o the large diameter end o the
rollers is worn level or below the other sur ace (Figure
17).
b. The radius at the large diameter end o the
rollers is worn to a sharp edge (Figure 17).
c. A visible groove in the cup or the cone inner
race sur aces. The groove can be seen at the small or
large diameter end o both parts (Figure 18).
FIGURE 18. Race surface wear indicators
d. Deep cracks or breaks in the cup, the cone
inner race, or the roller sur aces (Figure 18).
e. Bright wear marks on the outer sur ace o the
roller cage (Figure 19).
FIGURE 19. Roller cage wear indicators
. Damage on the rollers and on the sur aces o the
cup and cone inner race that touch the rollers (Figure
20).
FIGURE 20. Cup and cone wear indicators
g. Damage on the cup and cone inner sur aces
that touch the rollers (Figure 21).
FIGURE 21. Cup and cone wear indicators