1993 DODGE TRUCK Service Repair Manual

PROPELLER
SHAFTS
16-1

PROPELLER
SHAFTS
CONTENTS
page

GENERAL
INFORMATION
1
TORQUE SPECIFICATIONS
PROPELLER
SHAFT REPLACEMENT
8
UNIVERSAL
JOINT
REPLACEMENT

SERVICE
DIAGNOSIS/PROCEDURES
3
page

15
10

GENERAL INFORMATION

PROPELLER
SHAFTS
The basic function of a propeller shaft is to trans­
mit power from one point to another. The shaft is de­
signed to send torque through an angle from the
transmission (transfer case on 4WD vehicles) to the axle (Fig. 1). The propeller shaft must operate through con­
stantly changing relative angles between the trans­
mission and axle. It also must be capable of changing length while transmitting torque. The axle rides sus­
pended by springs in a floating motion. This means
the propeller shaft must contract, expand and change operating angles. This is accomplished through uni­
versal joints. The U-joints permit the propeller shaft
to operate at different angles. The slip joints (or
yokes) permit contraction or expansion.
Tubular propeller shafts are balanced by the man­
ufacturer with weights spot welded to the tube.
The propeller shaft is designed and built with the
yoke lugs in line with each other. This is called phas­ ing. This design produces the smoothest running con­
dition. An out of phase shaft can cause a vibration.
Before undercoating a vehicle, the propeller
shaft and the U-joints should be covered. This

SLIP
YOKE
BOOT
FRONT
PROPELLER SHAFT
REAR
PROPELLER SHAFT

Fig.
1 Front and Rear Propeller Shafts (4
WD)
J9216-23

16-2
PROPELLER SHAFTS

• will prevent the undercoating from causing an
unbalanced condition and vibration.
CAUTION: Use exact replacement
hardware
for at­

taching
the
propeller
shafts.
Exact replacement
will
ensure safe operation.
The specified
torque must

always
be
applied when tightening
the
fasteners.

UNIVERSAL
JOINTS
The front prop shaft uses the 7260 series universal
joint. The rear prop shaft uses the 7290 series uni­ versal joint on all but the Dana 70 axle. The 1410 se­
ries is used with the Dana 70 axle. Two different types of universal joints systems are
used:
• Single cardan universal joint (Fig. 2)
• Double cardan universal joint (Fig. 3)

LUBRICATION
The slip yoke on the front shaft is equipped with a
zerk type lubrication fitting. Use a multi-purpose NLGI Grade 2 EP lubricant. Refer to Group 0, Lubri­
cation and Maintenance for additional information.
The factory installed U-joints are lubricated for the life of the vehicle and do not need re-lubrication. All
RETAINER
J9216-20

Fig.
2
Single
Cardan Universal Joint
(Typical)
U-joints should be inspected for leakage and damage
each time the vehicle is serviced. If seal leakage or damage exists, the U-joint should be replaced.

1.
LINK YOKE

2.
SOCKET SPRING
3. SOCKET BALL RETAINER

4.
THRUST
WASHER

5.
NEEDLE BEARINGS
6.
SEAL

7.
BEARING
CAP
8.
REAR SPIDER

9.
SOCKET YOKE

10.
SOCKET BALL 11.
FRONT
SPIDER

12.
NEEDLE BEARINGS
13.
THRUST
WASHER

14.
DRIVE SHAFT YOKE

15.
RETAINING CLIP
Fig.
3
Double
Cardan (CV) Universal Joint

•

PROPELLER SHAFTS
16 - 3
SERVICE
DIAGNOSIS/PROCEDURES

INDEX

page page

Precautions . 3 Universal
Joint
Angle Measurement ............ 4

Runout
4
Vibration
3

Unbalance
3

PRECAUTIONS
Propeller shafts are balanced by the manufacturer
to prevent vibration. Before undercoating a vehicle, the propeller shaft and the U-joints should be cov­ered. This will prevent the undercoating from caus­
ing an unbalanced condition and vibration. Use exact replacement hardware for attaching the
propeller shafts. Exact replacement will ensure safe operation. The specified torque must always be ap­
plied when tightening the fasteners.

VIBRATION
Tires that are out-of-round or wheels that are un­
balanced will cause a low frequency vibration. Refer to Group 22, Tires And Wheels for service informa­
tion. Brake drums that are unbalanced will cause harsh,
low frequency vibration. Refer to Group 5, Brakes for
service information. Driveline vibration can also result from loose or
damaged engine mounts. Refer to Group 21, Trans­
missions for additional information. Propeller shaft vibration will increase as the vehi­
cle speed is increased. A vibration that occurs within a specific speed range is not caused by propeller
shaft unbalance. Defective U-joints or an incorrect
propeller shaft angle are usually the cause.

UNBALANCE
If propeller shaft unbalance is suspected, it can be
verified with the following procedure. Removing and re-indexing the propeller shaft
180° may eliminate some vibrations. (1) Raise and support the vehicle.
(2) Clean all foreign material from propeller shaft
and U-joints. (3) Inspect propeller shaft for missing balance
weights, broken welds, and bent areas. If the pro­
peller shaft is bent, it must be replaced. (4) Ensure the U-joints are not worn and are prop­
erly installed. (5) Check the U-joint clamp screws torque.
(6) Remove wheels and tires. Install wheel lug
nuts to retain brake drums in place. (7) Mark and number the shaft at four positions
90° apart, six inches from the yoke weld end.
DRIVELINE VIBRATION

Drive
Condition
Possible Cause
Correction

PROPiLLlR
SHAFT
a. Undercoating or other foreign material
on shaft.

b.
Loose U-joint clamp screws.
c. Loose or bent U-joint yoke or excessive runout.
d. Incorrect drive line angularity.
e. Rear spring center bolt not in seat.
f. Worn U-joint bearings. g. Propeller shaft damaged (bent tube) or out of balance.
h. Broken rear spring.
i. Excessive runout or unbalanced condition.

j.
Excessive drive pinion gear shaft yoke runout. a. Clean exterior of shaft and wash with
solvent.

b.
Tighten screws properly.
c. Install replacement yoke.
d. Correct angularity
e. Loosen spring U-bolts and seat center
bolts.

f. Replace U-joint. g. Install replacement propeller shaft.
h. Replace rear spring.
i. Reindex propeller shaft 180°, test and correct as necessary.

j.
Reindex propeller shaft 180° and evaluate.
UNIVERSAL
JOINT
NOISE a. U-joint clamp screws loose.

b.
Lack of lubrication. a. Tighten screws with specified torque.

b.
Replace U-joint.
J9216-7

16-4 PROPELLER SHAFTS

• (8) Run and accelerate the vehicle until vibration
occurs. Note the intensity and speed the vibration oc­
curred. Stop the engine. (9) Install a screw clamp at position I (Fig. 1).

Fig.
1 Clamp
Screw
At Position 1
(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, the vibration may not
be caused by propeller shaft unbalance. (12) If the vibration decreased, install a second
clamp (Fig. 2) and repeat the vibration test.

Fig.
2 Two
Clamp
Screws
At The
Same
Position
(13) If vibration increased, separate the clamp
screws (1/4 inch above and 1/4 inch below the mark).
Repeat the vibration test (Fig. 3).
(14) Increase distance between the clamp screws.
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) Install the wheel and tire. Remove supports
and lower the vehicle.
RF4B9
Fig.
3
Clamp
Screws
Separated (16) If the amount of vibration remains unaccept­

able,
apply procedures at the front end of propeller
shaft.
RUNOUT (1) Remove dirt, rust, paint, and undercoating
from the propeller shaft surface. Areas where the dial indicator will contact the shaft must be clean. (2) The dial indicator must be installed perpendic­
ular to the shaft surface. (3) Measure runout at the center and ends. (4) Refer to Runout Specifications chart.
(5) Replace the propeller shaft if the runout ex­
ceeds the limit.

RUNOUT
SPECIFICATIONS

Front of shaft 0.010 in. (0.25 mm)
Center of shaft . 0.015 in. (0.38 mm) Rear of
shaft
.
0.010
in. (0.25 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. Under 30 inches the max. runout is 0.20 inch for full length of
the
tube.

J9116-15

UNIVERSAL JOINT
ANGLE
MEASUREMENT
INFORMATION
When two shafts intersect, the bend that is formed
is called the working angle. The larger the angle, the
larger the amount of acceleration and deceleration of
the joint. This speeding up and slowing down of the
joint must be cancelled. This will produce a smooth power flow. This is done through phasing and proper universal joint working angles.

•

PROPELLER
SHAFTS
16-5 A propeller shaft is properly phased when the yoke
ends are on the same plane or in line. A twisted
shaft will throw the yokes out of phase and cause a
noticeable vibration.
When taking universal joint angle measurements
or checking phasing with two piece shafts, consider
each shaft separately. On 4WD vehicles, the front shaft input (pinion shaft) angle has priority over the
caster angle.
Ideally the driveline system should have:

•
Angles that are in equal or opposite within 1
degree of each other

•
Have a 3 degree maximum operating angle

•
Have at least a 1/2 degree continuous operat­
ing (propeller shaft) angle Engine speed (R.P.M.) is the main factor though in
determining maximum allowable operating angles.
As a guide to maximum normal operating angles re­
fer to the chart listed (Fig. 4).

PROPELLER
SHAFT
MAX*
NORMAL

R«P*JVi*
OPERATING
ANGLES

5000
3°

4500
3°

4000
4°

3500
5°

3000
5°

2500
7°

2000
8°
1500 11°
J9316-4

Fig.
4 Maximum
Angles
and
R.P.M.
INSPECTION
Before measuring universal joint angles, the
following must done.

•
Inflate all tires to correct pressure.

•
Check angles in the same loaded or unloaded condition as when the vibration occurred. Prop
shaft angles will change according to the
amount of load in the vehicle. Always check an­
gles in loaded and unloaded conditions.

•
Check the condition of all suspension components
and verify all fasteners are torqued to specifications.

•
Check the condition of the engine and transmis­
sion mounts and verify all fasteners are torqued to
specifications.

MEASUREMENT
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. Remove any external bearing snap rings (if equipped) from
universal joint so protractor base sits flat.
(1) Rotate the shaft until transmission/transfer
case output yoke bearing is facing downward.
Always make measurements from front to
rear. (2) Place Inclinometer on yoke bearing (A) parallel
to the shaft (Fig. 5). Center bubble in sight glass and
record measurement.
This measurement will give you the transmis­
sion or OUTPUT YOKE ANGLE (A).

Fig.
5 Front (Output)
Angle
Measurement (A)
(3) Rotate propeller shaft 90 degrees. Place Incli­
nometer on yoke bearing parallel to the shaft (Fig.
6).
Center bubble in sight glass and record measure­
ment. This measurement can also be taken at the
rear end of the shaft.
This measurement will give you the PROPEL­
LER SHAFT ANGLE (C). J9216-9

Fig.
6 Propeller Shaft
Angle
Measurement (C)

16 - 6
PROPELLER
SHAFTS

• (4) Subtract smaller figure from larger (C minus
A) to obtain transmission OUTPUT OPERATING
ANGLE. (5) Rotate propeller shaft 90 degrees and place In­
clinometer on pinion yoke bearing parallel to the
shaft (Fig. 7). Center bubble in sight glass and record
measurement.
This measurement will give you the pinion
shaft or INPUT YOKE ANGLE (B). (6) Subtract smaller figure from larger (C minus
B) to obtain axle INPUT OPERATING ANGLE. Refer to rules given below and the example in (Fig.
8) for additional information.
• Good cancellation of u-joint operating angles (with­
in 1°)
• Operating angles less than 3°
• At least 1/2 of one degree continuous operating (propeller shaft) angle
7663

(J-23498A)
J9216-12

Fig.
7 Rear
(input)
Angle
Measurement (B)
Horizontal Level
(A) Output Yoke = 3.0° 4.9° (B) Axle Input Yoke = 3.2° Qr 4.9°
(C) Prop. Shaft = 4.9° °r-3.0° (C) Prop. Shaft = 4.9° -3.2°
Transmission Output 1.9° Axle Input 1.7° Operating Angle Operating Angle
Trans.
Output Operating Angle 1.9°
Axle Input Operating Angle -1.7°
Amount of U-Joint Cancellation 0.2°

Fig.
8 Universal Joint
Angle
Example J9316-3

•

PROPELLER SHAFTS
16 - 7 ADJUSTMENT AT AXLE WITH LEAF SPRINGS
Adjust the pinion shaft angle at the springs with
tapered shims (Fig. 9). Install tapered shims between
the springs and axle pad to correct the angle. Refer to Group 3, Rear Suspension and Axle for additional information.
Fig. 9 Angle Adjustment at Leaf Springs
ADJUSTMENT AT CENTER BEARING WITH TWO-PIECE SHAFT
Drive away shudder is the vibration that occurs at
first acceleration from a stop. Shudder vibration usu­ ally peaks at the engines highest torque output.
Shudder is a symptom associated on vehicles using a two-piece prop shaft. Shudder can be decreased by
lowering the center bearing in 1/4 inch increments
with shim stock or fabricated plates (Fig. 10). Plate stock must be used to maintain compression of the
rubber insulator around the bearing. Do not use
washers. Replace the original bolts with the appro­
priate increased length bolts.
J9316-25

Fig. 10 Angle Adjustment at Center Bearing