Before undercoating a vehicle, the propeller
shaft and the U-joints should be covered to pre-
vent an out-of-balance condition and driveline
vibration.
CAUTION: Use original equipment replacement
parts for attaching the propeller shafts. The speci-
fied torque must always be applied when tightening
the fasteners.
DIAGNOSIS AND TESTING - PROPELLER
SHAFT
VIBRATION
Tires that are out-of-round, or wheels that are
unbalanced, will cause a low frequency vibration.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
Brake drums that are unbalanced will cause a
harsh, low frequency vibration. (Refer to 5 - BRAKES
- DIAGNOSIS AND TESTING)
Driveline vibration can also result from loose or
damaged engine mounts.
Propeller shaft vibration increases as the vehicle
speed is increased. A vibration that occurs within a
specific speed range is not usually caused by a pro-
peller shaft being unbalanced. Defective universal
joints, or an incorrect propeller shaft angle, are usu-
ally the cause of such a vibration.
Fig. 3 Rear Propeller Shaft - Dana Axles
1 - SLIDING YOKE
2 - PROPELLER SHAFT
3 - PINION YOKE
4 - CLAMP
5 - SCREW
6 - OUTPUT SHAFT
Fig. 4 Rear Propeller Shaft - Corporate Axles
1 - COMPANION FLANGE
2 - COMPANION YOKE
3 - REAR PROPELLER SHAFT
Fig. 5 Propeller Shaft And Yoke
1 - REFERENCE MARKS
BR/BEPROPELLER SHAFT 3 - 3
PROPELLER SHAFT (Continued)
DRIVELINE VIBRATION
Drive Condition Possible Cause Correction
Propeller Shaft Noise 1) Undercoating or other foreign
material on shaft.1) Clean exterior of shaft and wash
with solvent.
2) Loose U-joint clamp screws. 2) Install new clamps and screws
and tighten to proper torque.
3) Loose or bent U-joint yoke or
excessive runout.3) Install new yoke.
4) Incorrect driveline angularity. 4) Measure and correct driveline
angles.
5) Rear spring center bolt not in
seat.5) Loosen spring u-bolts and seat
center bolt.
6) Worn U-joint bearings. 6) Install new U-joint.
7) Propeller shaft damaged or out
of balance.7) Installl new propeller shaft.
8) Broken rear spring. 8) Install new rear spring.
9) Excessive runout or unbalanced
condition.9) Re-index propeller shaft, test,
and evaluate.
10) Excessive drive pinion gear
shaft runout.10) Re-index propeller shaft and
evaluate.
11) Excessive axle yoke deflection. 11) Inspect and replace yoke if
necessary.
12) Excessive transfer case runout. 12) Inspect and repair as necessary.
Universal Joint Noise 1) Loose U-joint clamp screws. 1) Install new clamps and screws
and tighten to proper torque.
2) Lack of lubrication. 2) Replace as U-joints as
necessary.
BALANCE
NOTE: Removing and re-indexing the propeller
shaft 180É relative to the yoke may eliminate some
vibrations.
If propeller shaft is suspected of being unbalanced,
it can be verified with the following procedure:
(1) Raise the vehicle.
(2) Clean all the foreign material from the propel-
ler shaft and the universal joints.
(3) Inspect the propeller shaft for missing balance
weights, broken welds, and bent areas.If the pro-
peller shaft is bent, it must be replaced.
(4) Inspect the universal joints to ensure that they
are not worn, are properly installed, and are cor-
rectly aligned with the shaft.
(5) Check the universal joint clamp screws torque.
(6) Remove the wheels and tires. Install the wheel
lug nuts to retain the brake drums or rotors.
(7) Mark and number the shaft six inches from the
yoke end at four positions 90É apart.(8) Run and accelerate the vehicle until vibration
occurs. Note the intensity and speed the vibration
occurred. Stop the engine.
(9) Install a screw clamp at position 1 (Fig. 6).
(10) Start the engine and re-check for vibration. If
there is little or no change in vibration, move the
clamp to one of the other three positions. Repeat the
vibration test.
(11) If there is no difference in vibration at the
other positions, the source of the vibration may not
be propeller shaft.
(12) If the vibration decreased, install a second
clamp (Fig. 7) and repeat the test.
(13) If the additional clamp causes an additional
vibration, separate the clamps (1/2 inch above and
below the mark). Repeat the vibration test (Fig. 8).
(14) Increase distance between the clamp screws
and repeat the test until the amount of vibration is
at the lowest level. Bend the slack end of the clamps
so the screws will not loosen.
3 - 4 PROPELLER SHAFTBR/BE
PROPELLER SHAFT (Continued)
(15) If the vibration remains unacceptable, apply
the same steps to the front end of the propeller shaft.
(16) Install the wheel and tires. Lower the vehicle.
RUNOUT
(1) Remove dirt, rust, paint and undercoating from
the propeller shaft surface where the dial indicator
will contact the shaft.
(2) The dial indicator must be installed perpendic-
ular to the shaft surface.
(3) Measure runout at the center and ends of the
shaft sufficiently far away from weld areas to ensure
that the effects of the weld process will not enter into
the measurements.
(4) Refer to Runout Specifications chart.
(5) If the propeller shaft runout is out of specifica-
tion, remove the propeller shaft, index the shaft 180É,
and re-install the propeller shaft. Measure shaft
runout again.
(6) If the propeller shaft runout is now within
specifications, mark the shaft and yokes for proper
orientation.
(7) If the propeller shaft runout is not within spec-
ifications, verify that the runout of the transmission/
transfer case and axle are within specifications.
Correct as necessary and re-measure propeller shaft
runout.
(8) Replace the propeller shaft if the runout still
exceeds the limits.
RUNOUT SPECIFICATIONS
Front of Shaft 0.020 in. (0.50 mm)
Center of Shaft 0.025 in. (0.63 mm)
Rear of Shaft 0.020 in. (0.50 mm)
note:
Measure front/rear runout approximately 3 inches
(76 mm) from the weld seam at each end of the
shaft tube for tube lengths over 30 inches. For
tube lengths under 30 inches, the maximum
allowed runout is 0.020 in. (0.50 mm) for the full
length of the tube.
STANDARD PROCEDURES
To accurately check driveline alignment, raise and
support the vehicle at the axles as level as possible.
Allow the wheels and propeller shaft to turn.
(1) Remove any external bearing snap rings, if
equipped, from universal joint so protractor base sits
flat.
(2) Rotate the shaft until transmission/transfer
case output yoke bearing is facing downward.
NOTE: Always make measurements from front to
rear and from the same side of the vehicle.
Fig. 6 Clamp Screw At Position 1
1 - CLAMP
2 - SCREWDRIVER
Fig. 7 Two Clamp Screws At The Same Position
Fig. 8 Clamp Screws Separated
1-1¤2INCH
BR/BEPROPELLER SHAFT 3 - 5
PROPELLER SHAFT (Continued)
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
mate and side gears. The side gears are splined to
the axle shafts.
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion mate shaft. This
occurs because input torque applied to the gears is
divided and distributed equally between the two side
gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 2).When turning corners, the outside wheel must
travel a greater distance than the inside wheel to
complete a turn. The difference must be compensated
for to prevent the tires from scuffing and skidding
through turns. To accomplish this, the differential
allows the axle shafts to turn at unequal speeds (Fig.
3). In this instance, the input torque applied to the
pinion gears is not divided equally. The pinion gears
now rotate around the pinion mate shaft in opposite
directions. This allows the side gear and axle shaft
attached to the outside wheel to rotate at a faster
speed.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, tooth contact, worn/damaged
gears or the carrier housing not having the proper
offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
Fig. 1 216 FBI Differential Cover
1 - FILL PLUG
2 - IDENTIFICATION TAG
3 - DIFFERENTIAL COVER
Fig. 2 Differential Operation-Straight Ahead Driving
1 - IN STRAIGHT AHEAD DRIVING EACH WHEEL ROTATES AT
100% OF CASE SPEED
2 - PINION GEAR
3 - SIDE GEAR
4 - PINION GEARS ROTATE WITH CASE
Fig. 3 Differential Operation-On Turns
1 - PINION GEARS ROTATE ON PINION SHAFT
BR/BEFRONT AXLE - 216FBI 3 - 13
FRONT AXLE - 216FBI (Continued)
cle turns. A worn pinion mate shaft can also cause a
snapping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial bearing noise is also constant and varies only
with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.
LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side-gear thrust washers. A worn
pinion shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by:
²Damaged drive shaft.²Missing drive shaft balance weight(s).
²Worn or out of balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front end components
or engine/transmission mounts. These components
can contribute to what appears to be a rear end
vibration. Do not overlook engine accessories, brack-
ets and drive belts.
All driveline components should be examined
before starting any repair.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged) can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear. Listen
for the noise, a mechanics stethoscope is helpful in
isolating the source of a noise.
3 - 14 FRONT AXLE - 216FBIBR/BE
FRONT AXLE - 216FBI (Continued)
DIAGNOSTIC CHART
Condition Possible Causes Correction
Wheel Noise 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Replace bearing.
Axle Shaft Noise 1. Misaligned axle tube. 1. Inspect axle tube alignment. Correct
as necessary.
2. Bent or sprung axle shaft. 2. Inspect and correct as necessary.
3. End-play in pinion bearings. 3. Refer to pinion pre-load information
and correct as necessary.
4. Excessive gear backlash between the
ring gear and pinion.4. Check adjustment of the ring gear
and pinion backlash. Correct as
necessary.
5. Improper adjustment of pinion gear
bearings.5. Adjust the pinion bearings pre-load.
6. Loose pinion yoke nut. 6. Tighten the pinion yoke nut.
7. Scuffed gear tooth contact surfaces. 7. Inspect and replace as necessary.
Axle Shaft Broke 1. Misaligned axle tube. 1. Replace the broken shaft after
correcting tube mis-alignment.
2 Vehicle overloaded. 2. Replace broken shaft and avoid
excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken shaft and avoid or
correct erratic clutch operation.
4. Grabbing clutch. 4. Replace broken shaft and inspect and
repair clutch as necessary.
Differential Cracked 1. Improper adjustment of the
differential bearings.1. Replace case and inspect gears and
bearings for further damage. Set
differential bearing pre-load properly.
2. Excessive ring gear backlash. 2. Replace case and inspect gears and
bearings for further damage. Set ring
gear backlash properly.
3. Vehicle overloaded. 3. Replace case and inspect gears and
bearings for further damage. Avoid
excessive vehicle weight.
4. Erratic clutch operation. 4. Replace case and inspect gears and
bearings for further damage. Avoid
erratic use of clutch.
Differential Gears Scored 1. Insufficient lubrication. 1. Replace scored gears. Fill differential
with the correct fluid type and quantity.
2. Improper grade of lubricant. 2. Replace scored gears. Fill differential
with the correct fluid type and quantity.
3. Excessive spinning of one wheel/tire. 3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.
BR/BEFRONT AXLE - 216FBI 3 - 15
FRONT AXLE - 216FBI (Continued)
Condition Possible Causes Correction
Loss Of Lubricant 1. Lubricant level too high. 1. Drain lubricant to the correct level.
2. Worn axle shaft seals. 2. Replace seals.
3. Cracked differential housing. 3. Repair as necessary.
4. Worn pinion seal. 4. Replace seal.
5. Worn/scored yoke. 5. Replace yoke and seal.
6. Axle cover not properly sealed. 6. Remove, clean, and re-seal cover.
Axle Overheating 1. Lubricant level low. 1. Fill differential to correct level.
2. Improper grade of lubricant. 2. Fill differential with the correct fluid
type and quantity.
3. Bearing pre-loads too high. 3. Re-adjust bearing pre-loads.
4. Insufficient ring gear backlash. 4. Re-adjust ring gear backlash.
Gear Teeth Broke 1. Overloading. 1. Replace gears. Examine other gears
and bearings for possible damage.
2. Erratic clutch operation. 2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.
3. Ice-spotted pavement. 3. Replace gears and examine
remaining parts for damage.
4. Improper adjustments. 4. Replace gears and examine
remaining parts for damage. Ensure ring
gear backlash is correct.
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct fluid
type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion contact
pattern.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched ring
gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out. Replace
components as necessary.
8. Loose differential bearing cap bolts. 8. Inspect differential components and
replace as necessary. Ensure that the
bearing caps are torqued tot he proper
specification.
9. Housing not machined properly. 9. Replace housing.
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the wheels and tires.
(3) Remove the brake calipers and rotors. Refer to
Group 5, Brakes, for proper procedures.(4) Remove ABS wheel speed sensors, if equipped.
Refer to Group 5, Brakes, for proper procedures.
(5) Disconnect the axle vent hose.
(6) Disconnect vacuum hose and electrical connec-
tor at disconnect housing.
(7) Remove the front propeller shaft.
3 - 16 FRONT AXLE - 216FBIBR/BE
FRONT AXLE - 216FBI (Continued)