Spicer Dodge 1999-2001 Light Duty Axle Applications - Manual (Page 7)

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How Limited Slip Differentials Operate
A conventional differential transmits all the ring gear torque through the differential gears to the axle shafts.
Torque is at all times equal on the axle shafts, and if one wheel slips, the other wheel can only put out as much
torque as the slipping wheel.
The Spicer Limited Slip differential has the same power flow as a conventional differential, plus a more direct flow
which automatically takes effect as driving conditions demand. This more direct power flow is from the differen-
tial case to each axle shaft through a clutch plate and disc arrangement.
Arrangement of these plates and discs is at the option of the vehicle manufacturer, so care should be taken
during disassembly to note the arrangement of these components.
The Limited Slip construction permits differential action when required for turning corners and transmits equal
torque to both wheels when driving straight ahead. However, when one wheel tries to spin due to leaving the
ground, a patch of ice, etc., the clutch packs automatically provide more torque to the wheel which is not trying
to spin.
The Limited Slip differential resists wheel spin on bumpy roads and provides more pulling power when one wheel
tries to slip. In many cases of differences in traction, pulling power will be automatically provided until both
wheels start to slip.
In diagnosis of vehicle operators' complaints, it is important to recognize two things.
1. If, with unequal traction, both wheels slip, the Limited Slip Differential has done all it can pssibly do.
2. In extreme cases of differences in traction, the wheel with the least traction may spin after the Limited . Slip
has transferred as much torque as possible to the non-slipping wheel.
How To Obtain Special Service Tools
Special service tools (see service manuals) can be obtained from the following company:
Kent-Moore
OE Tool and Equipment Group
SPX Corporation
28635 Mound Road
Warren MI 48092-3499
(800) 345-2233
All Models except Model 80 /286: The Powr-Lok
design is identified by its 2-piece case. The Trac-Lok
design is identified by its 1-piece case.
Model 80 /286 only: Both the Powr-Lok and the Trac-
Lok use 2-piece cases in the model 80 (286) axle. The
difference between the two is in the shape of the holes
for the cross shaft. The Powr-Lok case will have cross
shaft holes that are "U" shaped in one case half and "V"
shaped in the other case half. The Trac-Lok case will
have cross shaft holes that are semicircles in both case
halves.
It is also possible to replace an existing Powr-Lok unit
with a complete Trac-Lok unit. For this purpose, the
differential case assembly must be replaced.
How To Distinguish a Powr-Lok™ from a Trac-Lok™
POWR-LOK™
2-Piece Case
4 Pinion Mate Gears
TRAC-LOK™
1 or 2-Piece Case
2 Pinion Mate Gears