Dodge ram truck 3500 1996 Service Manual page 148

3 - 82 DIFFERENTIAL AND DRIVELINE B R
D E S C R I P T I O N A N D O P E R A T I O N ( C o n t i n u e d )
j AXLE % J
OUTER W H E E L 100% DIFFERENTIAL INNER W H E E L
110% CASE SPEED C A S E SPEED 9 0 % CASE SPEED
P I N I O N GEARS ROTATE
O N P I N I O N SHAFT J9303-14
Fig. 3 Differential Operation—On Turns
In the Trac-Lok/Power-Lok differential, part of the
ring gear torque is transmitted through clutch packs.
The clutch packs contain multiple disc clutches, that
have radial grooves on the plates and concentric
grooves on the discs.
Trac-Lok differentials can also use plates and discs
with bonded fiber material that is smooth in appear­
ance.
In operation, the Trac-Lok/Power-Lok clutches are
engaged by two concurrent forces. The first being
preload force exerted through dished spring washers
contained In the clutch packs. The second from sepa­
rating forces generated by the side gears as torque is
applied through the ring gear (Fig. 4).
The Trac-Lok design provides differential action
needed for' turning corners and for driving straight
ahead. However, when one wheel looses traction, the
clutch packs transfer additional torque to the wheel
having the most traction. Trac-Lok differentials resist
wheel spin on bumpy roads and provide more pulling
power when one wheel looses traction. Pulling power
is provided continuously until both wheels loose trac­
tion. I f both wheels slip due to unequal traction,
Trac-Lok operation is normal. I n extreme cases of dif­
ferences of traction, the wheel with the least traction
may spin.
D I A G N O S I S A N D T E S T I N G
GENERAL INFORMATION
Axle bearing problem conditions are usually caused
by:
• Insufficient or incorrect lubricant
• Foreign matter/water contamination
• Incorrect bearing preload torque adjustment
• Incorrect backlash (to tight)
When serviced, the bearings must be cleaned thor­
oughly. They should be dried with lint-free shop tow­
els. Never spin d r y bearings w i t h compressed
Fig. 4 Limited Slip Differential Operation—Both
Wheels Driving
air. This will overheat them and brinell the
bearing surfaces. This will result in noisy oper­
ation after repair.
Axle gear problem conditions are usually the result
of:
• Insufficient lubrication
• Incorrect or contaminated lubricant
• Overloading (excessive engine torque) or exceed­
ing vehicle weight capacity
• Incorrect clearance or backlash adjustment
Insufficient lubrication is usually the result of a
housing cover leak. I t can also be from worn axle
shaft or pinion gear seals. Check for cracks or porous
areas in the housing or tubes.
Using the wrong lubricant will cause overheating
and gear failure. Gear tooth cracking and bearing
spalling are indicators of this.
Axle component breakage is most often the result
of:
© Severe overloading
• Insufficient lubricant
• Incorrect lubricant
• Improperly tightened components
Overloading occurs when towing heavier than rec­
ommended loads. Component breakage can occur
when the wheels are spun excessively. Incorrect