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i i i - p l a c e b e f o r e c o n n e c t i n g t h e w i r e c o n n e c t o r .
The R W A L b r a k e exciter r i n g is "press f i t t e d " on the
differential case.
CAUTION: Whenever a rear axle is being serviced
or anytime it is to be rotated via the engine (or by
another means), RAISE BOTH REAR WHEELS off
the surface.
DIFFERENTIAL
DIAGNOSIS
W i t h n o r m a l t i r e t r a c t i o n conditions, engine torque
is divided evenly. W i t h l o w - t r a c t i o n surfaces, engine
torque is transferred t o the wheel w i t h the most t i r e
traction. W h e n diagnosing a suspected T r a c - L o k dif-
ferential p r o b l e m condition, i t is i m p o r t a n t t o re-
member: i f t h e tire t r a c t i o n i s u n e q u a l ( o r l o w ) a t
b o t h w h e e l s , b o t h w h e e l s w i l l " s l i p " o r " s p i n " .
W h e n extreme
differences
i n wheel-to-wheel
t i r e
t r a c t i o n exist, t h e wheel w i t h t h e least t i r e t r a c t i o n
w i l l continue " s p i n n i n g " regardless of the fact t h a t
m a x i m u m t o r q u e w a s transferred to t h e opposite
wheel.
Noise complaints i n v o l v i n g rear axles equipped
w i t h a T r a c - L o k differential should be t h o r o u g h l y
evaluated t o determine t h e source of the noise. Be-
fore t h e d i f f e r e n t i a l is disassembled for a n y type o f
noise complaint, the l u b r i c a n t should be replaced. A n
incorrect (or insufficient) l u b r i c a n t can cause noises
such as " c h a t t e r " a n d " m o a n " as w e l l as scoring of
the d i f f e r e n t i a l clutch plates and discs (which can re-
sult i n f a i l u r e o f the complete u n i t ) .
Generally, t h e most common T r a c - L o k differential
noise encountered is a " c h a t t e r " noise w h e n t u r n i n g
a street corner (i.e., t u r n i n g the vehicle 90 degrees).
A common cause of t h i s is incorrect or contaminated
lubricant. Replacing t h e axle gear l u b r i c a n t (and
adding M O P A R H y p o i d Gear L u b r i c a n t A d d i t i v e or
an equivalent f r i c t i o n modifier additive) w i l l correct
the
condition i n most instances. However, i f t h e
"chatter" persists, c l u t c h disc damage could have oc-
curred.
The f o l l o w i n g d r a i n a n d l u b r i c a n t replacement pro-
cedure should be used for possible e l i m i n a t i o n of
noise before r e p l a c i n g the differential.
WARNING: WHEN SERVICING VEHICLES WITH AN
AXLE EQUIPPED WITH A TRAC-LOK DIFFEREN-
TIAL, DO NOT USE THE ENGINE TO ROTATE THE
AXLE AND WHEELS UNLESS BOTH REAR WHEELS
ARE RAISED FROM THE SURFACE AND THE VEHI-
CLE
SUPPORTED. A TRAC-LOK
DIFFERENTIAL
EQUIPPED AXLE CAN EXERT ENOUGH DRIVING
FORCE (IF ONE WHEEL IS IN CONTACT WITH THE
SURFACE) TO CAUSE THE VEHICLE TO MOVE.
(1) W i t h t h e rear axle l u b r i c a n t a t n o r m a l operat-
i n g t e m p e r a t u r e , raise and support the vehicle (rear
wheels free t o rotate).
(2) Remove t h e f i l l hole p l u g from t h e d i f f e r e n t i a l
housing cover and remove as m u c h o f t h e l u b r i c a n t
as possible w i t h a suction p u m p .
(3) F i l l t h e differential housing w i t h M O P A R H y -
poid Gear L u b r i c a n t , or a n equivalent product. I n -
s t a l l t h e f i l l hole p l u g i n t h e cover a n d t i g h t e n i t
w i t h 34 N*m (25 ft-lbs) torque.
(4) S t a r t t h e engine, shift t h e t r a n s m i s s i o n t o
D R I V E (or a f o r w a r d gear) and increase t h e speed t o
a p p r o x i m a t e l y 40 m p h (64 km/h) for 10 m i n u t e s .
T h i s w i l l
t h o r o u g h l y circulate t h e l u b r i c a n t a n d
cause t h e temperature t o increase to t h e n o r m a l op-
e r a t i n g range.
(5) Stop t h e engine, remove t h e f i l l hole p l u g a n d
( w i t h a suction pump) remove as m u c h o f the l u b r i -
cant as possible.
(6) I n s t a l l 4 ounces of M O P A R H y p o i d Gear L u b r i -
cant A d d i t i v e (or a n equivalent friction modifier a d -
ditive)
i n t h e differential
housing.
R e f i l l t h e
differential housing to the correct level w i t h M O P A R
H y p o i d Gear L u b r i c a n t (or a n equivalent product).
I n s t a l l t h e f i l l hole p l u g and t i g h t e n i t w i t h 34 N»m
(25 ft-lbs) torque.
I f s u f f i c i e n t t i m e i s a v a i l a b l e , a f t e r r e p l a c i n g
t h e
l u b r i c a n t i n a T r a c - L o k d i f f e r e n t i a l , d r i v e
t h e v e h i c l e a n d m a k e 10 t o 12 s l o w ,
figure-eight
t u r n s . T h i s t y p e o f m a n e u v e r e n s u r e s t h a t t h e
r e p l a c e m e n t l u b r i c a n t i s p u m p e d t h r o u g h t h e
c l u t c h d i s c p a c k s .
(7) Lower the vehicle and r e t u r n i t t o t h e owner t o
drive a n d evaluate for approximately 100 miles (160
k m ) t o determine i f replacing t h e l u b r i c a n t corrects
the noise condition.
I f , a f t e r d r i v i n g t h e v e h i c l e a p p r o x i m a t e l y 100
m i l e s (160 k m ) , t h e d i f f e r e n t i a l n o i s e s t i l l o c c u r s ,
r e p l a c e t h e d i f f e r e n t i a l case ( w i t h i t s i n t e r n a l
c o m p o n e n t s ) . W i t h t h e e x c e p t i o n o f t h e r i n g g e a r
a n d
t h e d i f f e r e n t i a l b e a r i n g s , t h e d i f f e r e n t i a l
case a n d i t s i n t e r n a l c o m p o n e n t s a r e s e r v i c e d a s
a u n i t o n l y a n d s h o u l d n o t b e d i s a s s e m b l e d .
DIFFERENTIAL
TEST
(1) D r i v e the vehicle to thoroughly w a r m up the l u -
b r i c a n t i n t h e rear axle.
(2) Place a large piece of K r a f t paper (or a n equiv-
alent product) over a smooth Formica board (or a n
equivalent
product). E n s u r e
t h a t
t h e F o r m i c a
b o a r d i s o n a f l a t a n d l e v e l s u r f a c e .
(3) D r i v e t h e vehicle over the Formica board u n t i l
one rear wheel/tire is i n the center of t h e board a n d
the paper.
(4) Place a block of wood t h a t is 2-inches h i g h a n d
a m i n i m u m o f 3-inches wide i n front o f one o f t h e
f r o n t t i r e s .
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