Driveline Vibration - Jeep 1979 CJ-5 Technical & Service Manual

B E A R I N G
CAP
SOCKET
B A L L
R E T A I N E R
SOCKET
SPRING
L I N K
YOKE
SEAL
N E E D L E
. BEARINGS
THRUST
WASHER SOCKET
NEEDLE
PROPELLER B E A R I N G S
S H A F T
YOKE
F R O N T
SPIDER
Fig. 2E-6 Double Cardan Universal Joint
WASHER
T R U N N I O N
CAP
T R U N N I O N
B A L L
PROTECTIVE
BOOT
PROPELLER
S H A F T
T R U N N I O N
HOUSING
BOOT
R E T A I N I N G
STRAPS
8 0 3 3 5
Rg. 2E-7 Bill i l l T r u n i n Universal Joint
DRIVELINEVIBRATION
Driveline vibration can be divided into two categories:
audible or mechanical. Mechanical vibrations produce
visible motion in the fenders, rear view mirror, in-
strument panel, or steering wheel, or can be felt through
the seats, floorpan, or steering wheel. Audible vibra-
tions are heard or sensed above normal road and back-
ground noise and may be accompanied by mechanical
vibration. In some cases, audible vibration occurs as a
droning or drumming noise while in other cases, it pro-
duces a buffeting sensation that is felt or sensed by the
driver rather than heard.
Driveline vibration may be caused by the front or rear
propeller shafts, axle or transfer case yokes, universal
joints, incorrect front or rear pinion angles, loose en-
gine-transmission-transfer case mountings, or engine
driven accessories. Mechanical vibration is usually
caused by a damaged or worn driveline component. Au-
dible vibrations are usually caused by an incorrect uni-
versal joint angle or binding universal joints and are
most noticeable in the 40-60 mph (64-97 km/h) speed
range.
Vibration caused by a propeller shaft may be the
result of:
© Undercoating on the shaft tube
® Excessive shaft runout
® Cracked or broken shaft seam welds
® Dented, bent, or twisted shaft tube
• Worn or damaged shaft bearing yokes
• Loose universal joint clamp strap bolts, U-bolt nuts,
or flange bolts
• Tight, loose, or binding slip yoke
• Tight, worn, binding, or damaged universal joint
• Loose yoke retaining nut
Vibration caused by universal joints may be the result
of:
• Loose U-bolt nuts, clamp strap bolts, or flange bolts
• Tight, loose, binding, or worn slip yoke
• Worn or damaged universal joint spider
• Worn or damaged needle bearings or bearing caps
Vibration caused by axle, transfer case, engine, or
suspension components may be the result of:
© Loose yoke retaining nut
® Excessive yoke runout
• Incorrect universal joint angle
• Bent, worn, broken, or loose torque reaction bracket
or engine rear crossmember
• Damaged or loose suspension springs or suspension
components
• Loose engine or transmission/transfer case support
cushions or crossmembers, broken spring mounting
pad (on axle), broken spring center bolt, or damaged
engine driven accessories or drive belts.
Driveline Vibration Oiepesis
If a driveline vibration condition should develop, do
not initiate corrective procedures until the vibration
source has been determined. This is important in avoid-
ing unnecessary or ineffective repairs. The following
Diagnosis and Repair (DARS) Charts will help to isolate
the most common causes of driveline vibration: