Dodge Durango (DN). Manual — part 213

OPERATION

The propeller shaft must operate through con-

stantly changing relative angles between the trans-
mission and axle. It must also be capable of changing
length while transmitting torque. The axle rides sus-
pended by springs in a floating motion. The propeller
shaft must be able to change operating angles when
going over various road surfaces. This is accom-
plished through universal joints, which permit the
propeller shaft to operate at different angles. The slip
joints (or yokes) permit contraction or expansion (Fig.
2), (Fig. 3), and (Fig. 4).

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.

CENTER BEARING

DESCRIPTION

Vehicles equipped with a two-piece propeller shaft

uses a rubber insulated center bearing. The bearing
is used to support the shafts where they are joined
together.

OPERATION

The propeller shaft center bearing serves to divide

the required propeller shaft length into two smaller
shafts, which has several inherent advantages. Hav-
ing two short propeller shafts instead of one long
shaft decreases the chance of unwanted noise and
vibrations. The shorter shafts are easier to balance
and serve to increase ground clearance while main-
taining acceptable driveline angles.

Fig. 1 Reference Marks on Yokes

1 – REFERENCE MARKS

Fig. 2 Front Propeller Shaft

1 – REAR AXLE
2 – COMPANION FLANGE
3 – TRANSFER CASE
4 – FRONT PROPELLER SHAFT
5 – COMPANION YOKE
6 – FRONT AXLE
7 – COMPANION FLANGE
8 – REAR PROPELLER SHAFT
9 – COMPANION YOKE

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PROPELLER SHAFTS

DN

DESCRIPTION AND OPERATION (Continued)

Fig. 3 Rear Propeller Shaft with Center Bearing

1 – REAR AXLE
2 – REAR PROPELLER SHAFT

3 – TRANSMISSION EXTENSION HOUSING
4 – CENTER BEARING

Fig. 4 Rear Propeller Shaft

1 – REAR AXLE
2 – REAR PROPELLER SHAFT

3 – TRANSMISSION EXTENSION HOUSING

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PROPELLER SHAFTS

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DESCRIPTION AND OPERATION (Continued)

PROPELLER SHAFT JOINTS

DESCRIPTION

Two different types of propeller shaft joints are

used in AN vehicles (Fig. 5) and (Fig. 6). None of the
joints are serviceable. If worn or damaged, they must
be replaced as a complete assembly.

LUBRICATION

The factory installed universal joints are lubricated

for the life of the vehicle and do not need lubrication.
All universal joints should be inspected for leakage
and damage each time the vehicle is serviced. If seal
leakage or damage exists, the universal joint should
be replaced.

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.

Fig. 6 Double Cardan U-Joint

Fig. 5 Single Cardan U-Joint

1 – CROSS
2 – SEAL
3 – CAP AND NEEDLE BEARINGS

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PROPELLER SHAFTS

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DESCRIPTION AND OPERATION (Continued)

Ideally the driveline system should have;
• Angles that are equal or opposite within 1

degree of each other.

• Have a 3 degree maximum operating angle.

• Have at least a 1/2 degree continuous operating

(propeller shaft) angle.

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. 7).

DIAGNOSIS AND TESTING

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.

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.

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. 7 Maximum Angles And Propeller Shaft Speed

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PROPELLER SHAFTS

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DESCRIPTION AND OPERATION (Continued)