SUSPENSION
TABLE OF CONTENTS
page page
WHEEL ALIGNMENT.......................1
FRONT - 2WD............................7FRONT - 4WD...........................14
REAR..................................26
WHEEL ALIGNMENT
TABLE OF CONTENTS
page page
WHEEL ALIGNMENT
DESCRIPTION............................1
OPERATION.............................2
DIAGNOSIS AND TESTING..................2
PRE-ALIGNMENT........................2
STANDARD PROCEDURE...................2ALIGNMENT INDEPENDENT FRONT
SUSPENSION...........................2
CASTER CORRECTION MEASUREMENT.....3
ALIGNMENT LINK/COIL SUSPENSION........5
SPECIFICATIONS.........................6
WHEEL ALIGNMENT
DESCRIPTION
Wheel alignment is the positioning of the wheels in
relation to the vehicle. This is accomplished through
suspension and steering linkage adjustments. An
alignment is essential for efficient steering, good
directional stability and to minimize tire wear. The
most important measurements of an alignment are
caster, camber and toe position (Fig. 1) and (Fig. 2).
CAUTION: Do not attempt to modify any suspen-
sion or steering components by heating and bend-
ing.
NOTE: Periodic lubrication of the front suspension/
steering system components may be required. Rub-
ber bushings must never be lubricated. Refer to
Lubrication And Maintenance for the recommended
maintenance schedule.
Fig. 1 Alignment Angles - Independent Front
Suspension
1 - FRONT OF VEHICLE
2 - STEERING AXIS INCLINATION
3 - PIVOT POINT
4 - TOE-IN
BR/BESUSPENSION 2 - 1
OPERATION
²CASTERis the forward or rearward tilt of the
steering knuckle from vertical. Tilting the top of the
knuckle rearward provides positive caster. Tilting the
top of the knuckle forward provides negative caster.
Caster is a directional stability angle which enables
the front wheels to return to a straight ahead posi-
tion after turns.
²CAMBERis the inward or outward tilt of the
wheel relative to the center of the vehicle. Tilting the
top of the wheel inward provides negative camber.
Tilting the top of the wheel outward provides positive
camber. Incorrect camber will cause wear on the
inside or outside edge of the tire.
²WHEEL TOE POSITIONis the difference
between the leading inside edges and trailing inside
edges of the front tires. Incorrect wheel toe position
is the most common cause of unstable steering and
uneven tire wear. The wheel toe position is thefinal
front wheel alignment adjustment.
DIAGNOSIS AND TESTING - PRE-ALIGNMENT
Before starting wheel alignment, the following
inspection and necessary corrections must be com-
pleted. Refer to Suspension and Steering System
Diagnosis Chart for additional information.
(1) Inspect tires for size and tread wear.
(2) Set tire air pressure.
(3) Inspect front wheel bearings for wear.
(4) Inspect front wheels for excessive radial or lat-
eral runout and balance.
(5) Inspect ball studs, linkage pivot points and
steering gear for looseness, roughness or binding.
(6) Inspect suspension components for wear and
noise.
(7) Road test the vehicle.
STANDARD PROCEDURES - ALIGNMENT I.F.S.
Before each alignment reading the vehicle should
be jounced (rear first, then front). Grasp each
bumper at the center and jounce the vehicle up and
Fig. 2 Alignment Angles - Link/Coil
1 - WHEEL CENTERLINE
2 - NEGATIVE CAMBER ANGLE
3 - PIVOT CENTERLINE
4 - SCRUB RADIUS
5 - TRUE VERTICAL6 - KING PIN
7 - VERTICAL
8 - POSITIVE CASTER
2 - 2 WHEEL ALIGNMENTBR/BE
WHEEL ALIGNMENT (Continued)
down several times. Always release the bumper in
the down position.Set the front end alignment to
specifications while the vehicle is in its NOR-
MALLY LOADED CONDITION.
Camber and caster angle adjustments involve
changing the position of the upper suspension arm
pivot bar (Fig. 3). Refer to the Alignment Specifica-
tion Chart for the correct setting.
CASTER:Move the rear position of the pivot bar
in or out. This will change the caster angle signifi-
cantly and camber angle only slightly. To retain cam-
ber move the forward pivot very slightly in the
opposite direction.
NOTE: For example, to increase a positive caster
angle, move the rear position of the pivot bar
inward (toward the engine). Move the front of pivot
bar outward (away from the engine) slightly until
the original camber angle is obtained.CAMBER:Move the forward position of the pivot
bar in or out. This will change the camber angle sig-
nificantly and caster angle only slightly. The camber
angle should be adjusted as close as possible to the
preferred service specification. After adjustment
is made tighten pivot bar nuts to specifications.
TOE POSITION:The wheel toe position adjust-
ment should be the final adjustment.
(1) Start the engine and turn wheels both ways
before straightening the wheels. Center and secure
the steering wheel and turn off engine.
(2) Loosen the tie rod adjustment sleeve clamp
bolts/nuts.
NOTE: Each front wheel should be adjusted for
one-half of the total toe position specification. This
will ensure the steering wheel will be centered
when the wheels are positioned straight-ahead.
(3) Adjust the wheel toe position by turning the tie
rod adjustment sleeves as necessary.
STANDARD PROCEDURES - CASTER
CORRECTION MEASUREMENT
NOTE: To determine the correct caster alignment
angle for Cab-Chassis vehicles the following proce-
dure must be performed.
NOTE: 4x2 11000 GVW has a solid front axle and
uses a 4x4 frame.
(1) Take a height measurement to the center of the
front gauge hole in the frame. Take another measure-
ment to the center of the rear spring hanger bolt
(Fig. 4). Take these measurements on both sides of
the vehicle.
(2) Subtract the front measurement from the rear
measurement and use the average between the right
and left side. Use this number (caster correlation
valve) with the Corrected Caster Chart to obtain the
preferred caster angle.
Fig. 3 Caster Camber Adjustment Location
1 - PIVOT BAR
2 - UPPER SUSPENSION ARM
3 - SUSPENSION ARM FRAME MOUNT
4 - ADJUSTMENT SLOTS
BR/BEWHEEL ALIGNMENT 2 - 3
WHEEL ALIGNMENT (Continued)
CORRECTED CASTER CHART-CAB CHASSIS
Caster
Correlation
Value
(inches)4x2 8800
lb. GVW
134.7 in.
wheel
base4x4 8800
lb. GVW
4x2 & 4x4
11000 lb.
GVW
134.7 &
138.7 in.
wheel
base4x2 & 4x4
11000 lb.
GVW 162.7
in. wheel
base
Caster61
deg.Caster61
deg.Caster61
deg.
þ5.00 4.27É 3.77É 3.81É
þ4.75 4.39É 3.89É 3.91É
þ4.50 4.51É 4.01É 4.01É
þ4.25 4.64É 4.14É 4.11É
þ4.00 4.76É 4.26É 4.21É
þ3.75 4.88É 4.38É 4.31É
þ3.50 5.00É 4.50É 4.41É
þ3.25 5.12É 4.62É 4.51É
þ3.00 5.25É 4.75É 4.61É
þ2.75 5.37É 4.87É 4.71É
þ2.50 5.49É 4.99É 4.81É
þ2.25 5.61É 5.11É 4.91É
þ2.00 5.74É 5.24É 5.01É
þ1.75 5.86É 5.36É 5.11É
þ1.50 5.98É 5.48É 5.21É
þ1.25 6.10É 5.60É 5.31É
þ1.00 6.23É 5.73É 5.41É
þ0.75 6.33É 5.83É 5.51É
þ0.50 6.47É 5.97É 5.61É
þ0.25 6.59É 6.09É 5.71É
0.00 6.71É 6.21É 5.81É
STANDARD PROCEDURES - ALIGNMENT
LINK/COIL SUSPENSION
Before each alignment reading the vehicle should
be jounced (rear first, then front). Grasp each
bumper at the center and jounce the vehicle up and
down several times. Always release the bumper in
the down position.Set the front end alignment to
specifications while the vehicle is in its NOR-
MALLY LOADED CONDITION.
CAMBER:The wheel camber angle is preset and
is not adjustable.
CASTER:Check the caster of the front axle for
correct angle. Be sure the axle is not bent or twisted.Road test the vehicle and make left and right turn.
Observe the steering wheel return-to-center position.
Low caster will cause poor steering wheel returnabil-
ity.
Caster can be adjusted by rotating the cams on the
lower suspension arm (Fig. 5). (Refer to 2 - SUSPEN-
SION/WHEEL ALIGNMENT - STANDARD PROCE-
DURE).
TOE POSITION:The wheel toe position adjust-
ment should be the final adjustment.
(1) Start the engine and turn wheels both ways
before straightening the wheels. Center and Secure
the steering wheel and turn off engine.
(2) Loosen the adjustment sleeve clamp bolts.
(3) Adjust the right wheel toe position with the
drag link. Turn the sleeve until the right wheel is at
the correct TOE-IN position. Position clamp bolts to
their original position and tighten to specifications.
Make sure the toe setting does not change dur-
ing clamp tightening.
(4) Adjust left wheel toe position with tie rod at
left knuckle. Turn the sleeve until the left wheel is at
the correct TOE-IN position. Position clamp bolts to
their original position and tighten to specifications.
Make sure the toe setting does not change dur-
ing clamp tightening.
(5) Verify the right toe setting.
Fig. 5 Adjustment Cam
1 - ADJUSTMENT CAM
2 - AXLE BRACKET
3 - BRACKET REINFORCEMENT
4 - LOWER SUSPENSION ARM
BR/BEWHEEL ALIGNMENT 2 - 5
WHEEL ALIGNMENT (Continued)
(3) Position the indicator plunger against the
upper ball stud boss of the steering knuckle.
(4) Grasp the top of the tire and apply force in and
out. Look for movement at the ball joint between the
upper suspension arm and steering knuckle.
(5) If lateral movement is greater than 0.8 mm
(0.030 in.), replace the suspension arm.
UPPER CONTROL ARM
REMOVAL
(1) Raise and support vehicle.
(2) Remove tire and wheel assembly.
(3) Support lower suspension arm at outboard end
with jack stand.(4) Remove upper ball joint cotter pin and nut.
(5) Separate ball joint from knuckle with remover
MB-990635.
(6) Remove pivot bar bolts from upper suspension
arm bracket and remove arm from vehicle (Fig. 7).
INSTALLATION
(1) Position the upper suspension arm on the
bracket and install the pivot bar bolts. Tighten to
169 N´m (125 ft. lbs.).
(2) Install the ball joint in the knuckle. Install the
nut and tighten to 81 N´m (60 ft. lbs.) and replace-
ment the cotter pin.
(3) Remove the jack from the lower suspension
arm.
(4) Install the tire and wheel assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(5) Remove the support and lower the vehicle.
(6) Align the front suspension, (Refer to 2 - SUS-
PENSION/WHEEL ALIGNMENT - STANDARD
PROCEDURE).
Fig. 6 STABILIZER BAR
1 - STABILIZER BAR
2 - GROMMET
3 - GROMMET
4 - LINK
Fig. 7 Upper Suspension Arm
1 - PIVOT BAR
2 - UPPER SUSPENSION ARM
3 - SUSPENSION ARM FRAME MOUNT
4 - ADJUSTMENT SLOTS
BR/BEFRONT - 2WD 2 - 13
UPPER BALL JOINT (Continued)
FRONT - 4WD
TABLE OF CONTENTS
page page
FRONT - 4WD
DESCRIPTION...........................14
SPECIFICATIONS........................15
SPECIAL TOOLS.........................16
HUB / BEARING
REMOVAL..............................16
INSTALLATION...........................18
KNUCKLE
DESCRIPTION...........................20
OPERATION.............................20
REMOVAL..............................20
INSTALLATION...........................20
LOWER CONTROL ARM
REMOVAL..............................20
INSTALLATION...........................20
SHOCK
DESCRIPTION...........................21
OPERATION.............................21
DIAGNOSIS AND TESTING.................21
SHOCK..............................21
REMOVAL..............................21
INSTALLATION...........................21
SPRING
DESCRIPTION...........................22OPERATION.............................22
REMOVAL..............................22
INSTALLATION...........................22
STABILIZER BAR
DESCRIPTION...........................22
OPERATION.............................22
REMOVAL..............................22
INSTALLATION...........................23
TRACK BAR
DESCRIPTION...........................23
OPERATION.............................23
DIAGNOSIS AND TESTING.................23
TRACK BAR...........................23
REMOVAL..............................23
INSTALLATION...........................23
UPPER CONTROL ARM
REMOVAL..............................23
INSTALLATION...........................24
LOWER BALL JOINT
REMOVAL..............................24
INSTALLATION...........................25
UPPER BALL JOINT
REMOVAL..............................25
INSTALLATION...........................25
FRONT - 4WD
DESCRIPTION
The link/coil suspension allows each wheel to adapt
to different road surfaces. The suspension is com-
prised of (Fig. 1) :
²Shock absorbers
²Coil springs
²Upper and lower suspension arms
²Stabilizer bar
²Track bar
²Steering Knuckles
²Hub/Bearing
²Ball Joints
²Jounce Bumpers
CAUTION: Components attached with a nut and cot-
ter pin must be torqued to specification. Then if the
slot in the nut does not line up with the cotter pin
hole, tighten nut until it is aligned. Never loosen the
nut to align the cotter pin hole.CAUTION: Suspension components with rubber
bushings (except stabilizer bar) should be tightened
with the vehicle at normal height. It is important to
have the springs supporting the weight of the vehi-
cle when the fasteners are torqued. If springs are
not at their normal ride position, vehicle ride com-
fort could be affected and premature bushing wear
may occur.
DESCRIPTION
The upper and lower suspension arms use bush-
ings to isolate road noise. The suspension arms are
bolted to the frame and axle through the rubber
bushings. The lower suspension arm uses cam bolts
at the axle to allow for caster and pinion angle
adjustment.
2 - 14 FRONT - 4WDBR/BE
FRONT AXLE - 216FBI
TABLE OF CONTENTS
page page
FRONT AXLE - 216FBI
DESCRIPTION...........................12
OPERATION.............................12
DIAGNOSIS AND TESTING.................13
AXLE................................13
REMOVAL..............................16
INSTALLATION...........................17
ADJUSTMENTS..........................17
SPECIFICATIONS........................25
SPECIAL TOOLS.........................25
AXLE SHAFTS
REMOVAL..............................28
INSTALLATION...........................28
AXLE SHAFTS - INTERMEDIATE
REMOVAL..............................28
INSTALLATION...........................28
AXLE SHAFT SEALS
REMOVAL..............................29
INSTALLATION...........................29
AXLE VACUUM MOTOR
DESCRIPTION...........................29
OPERATION.............................30
DIAGNOSIS AND TESTING.................31VACUUM MOTOR.......................31
REMOVAL..............................33
DISASSEMBLY...........................33
ASSEMBLY.............................33
INSTALLATION...........................33
SINGLE CARDAN UNIVERSAL JOINTS
REMOVAL..............................33
INSTALLATION...........................34
PINION SEAL
REMOVAL..............................34
INSTALLATION...........................34
DIFFERENTIAL
REMOVAL..............................36
DISASSEMBLY...........................36
ASSEMBLY.............................37
INSTALLATION...........................37
DIFFERENTIAL CASE BEARINGS
REMOVAL..............................39
INSTALLATION...........................39
PINION GEAR/RING GEAR
REMOVAL..............................40
INSTALLATION...........................42
FRONT AXLE - 216FBI
DESCRIPTION
The housing for the 216 Front Beam-design Iron
(FBI) axles consists of an iron center casting with
tubes on each side. The tubes are pressed into and
welded to the differential housing.
The integral type housing, hypoid gear design has
the centerline of the pinion set below the centerline
of the ring gear.
The axle has a vent used to relieve internal pres-
sure caused by lubricant vaporization and internal
expansion.
The axles are equipped with semi-floating axle
shafts, meaning that loads are supported by the hub
bearings. The axle shafts are retained by nuts at the
hub bearings. The hub bearings are bolted to the
steering knuckle at the outboard end of the axle tube
yoke. The hub bearings are serviced as an assembly.
The axles are equipped with ABS brake sensors.
The sensors are attached to the knuckle assemblies
and the tone rings are pressed onto the axle shaft.
Use care when removing axle shafts as NOT to
damage the tone wheel or the sensor.The stamped steel cover provides a means for
inspection and servicing the differential.
The 216 axle have the assembly part number and
gear ratio listed on a tag. The tag is attached to the
housing cover by one of the cover bolts. Build date
identification codes are stamped on the cover side of
a axle tube.
The differential case is a one-piece design. The dif-
ferential pinion mate shaft is retained with a roll
pin. Differential bearing preload and ring gear back-
lash is adjusted by the use of shims. The shims are
located between the differential bearing cones and
case. Pinion bearing preload is set and maintained by
the use of a collapsible spacer.
The axle differential covers can be used for identi-
fication of the axle (Fig. 1). A tag is also attached to
the cover.
OPERATION
The axle receives power from the transfer case
through the front propeller shaft. The front propeller
shaft is connected to the pinion gear which rotates
the differential through the gear mesh with the ring
gear bolted to the differential case. The engine power
is transmitted to the axle shafts through the pinion
3 - 12 FRONT AXLE - 216FBIBR/BE
(8) Disconnect the stabilizer bar links at the axle
brackets.
(9) Disconnect the shock absorbers from axle
brackets.
(10) Disconnect the track bar from the axle
bracket.
(11) Disconnect the tie rod and drag link from the
steering knuckles.
(12) Position the axle with a suitable lifting device
under the axle assembly.
(13) Secure axle to lifting device.
(14) Mark suspension alignment cams for installa-
tion reference.
(15) Disconnect the upper and lower suspension
arms from the axle bracket.
(16) Lower the axle. The coil springs will drop
with the axle.
(17) Remove the coil springs from the axle bracket.
INSTALLATION
CAUTION: Suspension components with rubber
bushings should be tightened with the weight of the
vehicle on the suspension, at normal height. If
springs are not at their normal ride position, vehicle
ride comfort could be affected and premature bush-
ing wear may occur. Rubber bushings must never
be lubricated.
(1) Support the axle on a suitable lifting device.
(2) Secure axle to lifting device.
(3) Position the axle under the vehicle.
(4) Install the springs, retainer clip and bolts.
(5) Raise the axle and align it with the spring
pads.
(6) Position the upper and lower suspension arms
in the axle brackets. Install bolts, nuts and align the
suspension alignment cams to the reference marks.
Do not tighten at this time.
(7) Connect the track bar to the axle bracket and
install the bolt. Do not tighten at this time.
(8) Install the shock absorber and tighten bolts to
121 N´m (89 ft. lbs.) torque.
(9) Install the stabilizer bar link to the axle
bracket. Tighten the nut to 37 N´m (27 ft. lbs.)
torque.
(10) Install the drag link and tie rod to the steer-
ing knuckles and tighten the nuts to 88 N´m (65 ft.
lbs.) torque.
(11) Install the ABS wheel speed sensors, if
equipped. Refer to group 5, Brakes, for proper proce-
dures.
(12) Install the brake calipers and rotors. Refer to
Group 5, Brakes, for proper procedures.
(13) Connect the vent hose to the tube fitting.
(14) Connect vacuum hose and electrical connector
to disconnect housing.(15) Install front propeller shaft.
(16) Check and add differential lubricant, if neces-
sary. Refer to Lubricant Specifications in this section
for lubricant requirements.
(17) Install the wheel and tire assemblies.
(18) Remove the supports and lower the vehicle.
(19) Tighten the upper suspension arm nuts at
axle to 121 N´m (89 ft. lbs.) torque. Tighten the
upper suspension arm nuts at frame to 84 N´m (62 ft.
lbs.) torque.
(20) Tighten the lower suspension arm nuts at
axle to 84 N´m (62 ft. lbs.) torque. Tighten the lower
suspension arm nuts at frame to 119 N´m (88 ft. lbs.)
torque.
(21) Tighten the track bar bolt at the axle bracket
to 176 N´m (130 ft. lbs.) torque.
(22) Check the front wheel alignment.
ADJUSTMENTS
Ring and pinion gears are supplied as matched
sets only. The identifying numbers for the ring and
pinion gear are etched into the face of each gear (Fig.
4). A plus (+) number, minus (±) number or zero (0) is
etched into the face of the pinion gear. This number
is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
etched with a (0). The standard setting from the cen-
ter line of the ring gear to the back face of the pinion
is 109.5 mm (4.312 in.). The standard depth provides
the best gear tooth contact pattern. Refer to Back-
lash and Contact Pattern in this section for addi-
tional information.
Compensation for pinion depth variance is
achieved with a select shim/oil baffle. The shims are
placed between the rear pinion bearing and the pin-
ion gear head (Fig. 5).
Fig. 4 Pinion Gear ID Numbers
1 - PRODUCTION NUMBERS
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
BR/BEFRONT AXLE - 216FBI 3 - 17
FRONT AXLE - 216FBI (Continued)