Spicer Axle General Information - Manual (Page 6)

GENERAL INFORMATION
XGI
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 differential 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 possibly 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 companies:
Miller Special Tools T & D Machine Products
28635 Mound Road 4859 Convair Dr
Warren MI 48092-3499 Carson City, NV 89705
(800) 801-5420 (775) 884-2292
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POWR-LOK™
2-Piece Case
4-Pinion Mate Gears
TRAC-LOK™
1-Piece Case
2-Pinion Mate Gears
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™