exj 3, JEEP Manuals, Electronic Service Manual (jeep cherokee xj do 2000)
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DIFFERENTIAL AND DRIVELINE
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DIFFERENTIAL AND DRIVELINE
TABLE OF CONTENTS
page
page
1
6
5
3
PROPELLER SHAFTS
TABLE OF CONTENTS
page
page
DESCRIPTION AND OPERATION
DIAGNOSIS AND TESTING
SERVICE PROCEDURES
DRIVELINE ANGLE MEASUREMENT
REMOVAL AND INSTALLATION
DISASSEMBLY AND ASSEMBLY
CLEANING AND INSPECTION
ADJUSTMENTS
SPECIFICATIONS
SPECIAL TOOLS
DESCRIPTION AND OPERATION
ment parts helps to ensure safe operation. All fasten-
ers must be torqued to the specified values for safe
operation.
Also make alignment reference marks (Fig. 1) on
the propeller shaft yoke and axle, or transmission,
yoke prior to servicing. This helps to eliminate possi-
ble vibration.
PROPELLER SHAFT
DESCRIPTION
A propeller shaft (Fig. 2) is the shaft which con-
nects the transmission/transfer case to the axle dif-
ferential. This is the link through which the engine
power is transmitted to the axle.
The propeller shaft is designed and built with the
yoke lugs in line with each other which is called zero
phasing. This design produces the smoothest running
condition, an out-of-phase shaft can cause a vibra-
tion.
Tubular propeller shafts are balanced by the man-
ufacturer with weights spot welded to the tube.
CAUTION: Do not allow the propeller shaft to drop
or hang from any propeller shaft joint during
removal. Attach the propeller shaft to the vehicle
underside with wire to prevent damage to the joints.
OPERATION
The propeller shaft must operate through con-
stantly changing relative angles between the trans-
mission and axle when going over various road
surfaces. It must also be capable of changing length
while transmitting torque. The axle rides suspended
by springs in a floating motion.This is accomplished
through universal joints, which permit the propeller
PRECAUTIONS
Use the exact replacement parts when installing
the propeller shafts. The use of the correct replace-
3 - 2
PROPELLER SHAFTS
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DESCRIPTION AND OPERATION (Continued)
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.
PROPELLER SHAFT JOINTS
DESCRIPTION
Two different types of propeller shaft joints are
used:
²
Single cardan universal joint (Fig. 3)
Fig. 1 Reference Marks on Yokes
1 – REFERENCE MARKS
Double cardan (CV) universal joint (Fig. 4)
None of the universal joints are serviceable. If one
becomes worn or damaged, the complete universal
joint assembly must be replaced.
²
shaft to operate at different angles. The slip joints (or
yokes) permit contraction or expansion (Fig. 2).
Fig. 2 Propeller Shafts
1 – FRONT AXLE
2 – FRONT PROPELLER SHAFT
3 – TRANSFER CASE
4 – BOOT
5 – REAR AXLE
6 – STRAP
7 – REAR PROPELLER SHAFT
8 – STRAP
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PROPELLER SHAFTS
3 - 3
DESCRIPTION AND OPERATION (Continued)
PROPELLER SHAFT JOINT ANGLE
DESCRIPTION
When two shafts come together at a common joint,
the bend that is formed is called the operating angle.
The larger the angle, the larger the amount of angu-
lar acceleration and deceleration of the joint. This
speeding up and slowing down of the joint must be
cancelled to produce a smooth power flow.
OPERATION
This cancellation is done through the phasing of a
propeller shaft and ensuring that the proper propel-
ler shaft joint working angles are maintained.
A propeller shaft is properly phased when the yoke
ends are in the same plane, or in line. A twisted
shaft will make the yokes out of phase and cause a
noticeable vibration.
When taking propeller shaft joint angle measure-
ments, or checking the phasing, of two piece shafts,
consider each shaft separately.
Ideally the driveline system should have;
²
Fig. 3 Single Cardan Universal Joint
1 – NEEDLE BEARING
6 – BEARING CAP
Angles
that
are
equal
or
opposite
within
1
2 – BEARING CAP
7 – RETAINING CLIP
degree of each other.
²
3 – SEAL
8 – YOKE
Have a 3 degree maximum operating angle.
4 – SPIDER
9 – SEAL
Have at least a 1/2 degree continuous operating
(propeller shaft) angle.
²
5 – NEEDLE BEARING
Fig. 4 Double Cardan (CV) Universal Joint
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PROPELLER SHAFTS
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DESCRIPTION AND OPERATION (Continued)
DIAGNOSIS AND TESTING
Propeller shaft speed (rpm) is the main factor in
determining the maximum allowable operating angle.
As a guide to the maximum normal operating angles
refer to (Fig. 5).
VIBRATION
Tires that are out-of-round, or wheels that are
unbalanced, will cause a low frequency vibration.
Refer to Group 22, Tires and Wheels, for additional
information.
Brake drums that are unbalanced will cause a
harsh, low frequency vibration. Refer to Group 5,
Brakes, for additional information.
Driveline vibration can also result from loose or
damaged engine mounts. Refer to Group 9, Engines,
for additional information.
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.
PROPELLER SHAFT
MAX. NORMAL
R.P.M.
OPERATING ANGLES
5000
3°
4500
3°
4000
4°
3500
5°
3000
5°
2500
7°
2000
8°
1500
11°
Fig. 5 Maximum Angles And Propeller Shaft Speed
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.
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PROPELLER SHAFTS
3 - 5
DIAGNOSIS AND TESTING (Continued)
UNBALANCE
NOTE: Removing and re-indexing the propeller
shaft 180° 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 90° 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).
Fig. 7 Two Clamp Screws At The Same Position
(13) If the additional clamp causes an additional
vibration, separate the clamps (1/4 inch above and
below the mark). Repeat the vibration test (Fig. 8).
Fig. 8 Clamp Screws Separated
1–
1
⁄
2
INCH
(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.
(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.
Fig. 6 Clamp Screw At Position 1
1 – CLAMP
2 – SCREWDRIVER
RUNOUT
(1) Remove dirt, rust, paint, and undercoating
from the propeller shaft surface where the dial indi-
cator 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.
(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.
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