4WHEELOFFROAD.COM 4-WHEEL & OFF-ROADNOVEMBER 2019 15
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ELECTING THE BEST LIMITED-
slip or locking differential for
your 4x4 depends on many
factors, including the type of
off-roading you do, how much
time you spend off-road, your
driving style and personal
preference, and your budget. In most cases
there isn’t one silver-bullet traction-adding
device that will work great for every
vehicle, driver, and specific use. There will
always be compromises. The good news
is that we are here to steer you in the right
direction. We’ll help you determine which
locker or limited slip will work best for you.
First, you have to decide if you want a
limited-slip or locking differential and in
what axles to put them in. If you spend most
of your time on the street and only venture
lightly off-road, then you may find that the
stock open differentials suit your needs. To
venture a little farther up the trails or to
handle on-road snow and ice, you might
want to consider a rear limited slip and pos-
sibly a front one too. For trails with more
staggered holes and situations where
wheels lift off the ground, you’ll find that a
rear locking differential will generally take
you farther than front and rear limited slips.
Those of you who don’t want to ever be
traction limited off-road should look into
locking differentials front and rear.
Many traction-adding devices have less
than ideal handling quirks on-road, and
sometimes the quirks surface off-road
too. In most cases a limited-slip differen-
tial will operate as seamlessly as a factor y
open differential. Selectable lockers are a
great choice for those who need the trac-
tion advantage of a true locking differen-
tial while still maintaining streetability for
commuting. These lockers can be turned
on and off, providing predictable and sta-
ble open-differential performance on the
street and when making sharp turns off-
road. They can be operated by a variety of
methods depending on the brand, includ-
ing a 12-volt switch, air pressure, or a cable
shif ter. Die - hard of f- road fanatics will of ten
choose automatic locking differentials or a
rear spool for cost savings, simplicity, and
reliability, taking in stride any of the han -
dling quirks that may arise.
Keep in mind that not all traction -adding
devices are compatible with every 4x4.
Many newer 4x4s with ABS and stability
control systems don’t play well with auto-
matic locking differentials, so it’s important
to ask a lot of questions before shelling out
your hard-earned cash for a traction adder.
In most cases, newer 4x4s will require a
limited-slip or selectable locker to keep the
dash from lighting up with warning lights.
DIFFERENTIAL TYPE CASE STYLE ENGAGEMENT METHOD PROS CONS CHARACTERISTICS
ARB Air Locker Mechanical
locking
differential
Full case
replacement
Selectable, internal air
engagement
Benefits of open
differential
when unlocked.
Arguably the
strongest locker
available.
Requires air
source. Air lines
are fragile. Internal
air leaks will cause
it not to function.
Cannot be
manually operated
in an emergency.
Engages and
disengages quickly.
Great choice for front
differentials and
front and rear in daily
driven 4x4s.
Auburn HP,
Pro, and
Race
Series
Cone-clutch
limited slip
Full case
replacement
Automatic Great for front axle
application. The
d-Rex program
allows for factory
rebuild when worn.
Not a locker.
Clutches will
eventually wear
out. Cannot be
rebuilt at home.
Functions as an
aggressive limited
slip. Pro and Race
Series versions offer
a n even b etter tor q u e
bias.
Auburn Ected Max Clutch type
limited slip with
clutch locking
differential
capability
Full case
replacement
Selectable, 12-volt
electric engagement
Limited slip when
unlocked, locker
when engaged.
Limited slip feature
great for on-road
snow and ice. Can
be rebuilt at home.
Clutch discs can
wear. 12-volt
wire could be
vulnerable.
Requires friction
modifier in oil to
reduce chatter.
Good all-around
on- and off-road
limited-slip and
locking differential
for applications that
see snow and ice.
Auburn
Max
Lock
Mechanical
locking
differential
Drop in stock
case
Automatic Inexpensive. Easy
setup.
Stock differential
case is usually the
weak point.
Great way to test
the waters to see if
you really want to
upgrade to a full case
locker.
Torq-Masters
Aussie
Locker
Mechanical
locking
differential
Drop in stock
case
Automatic Inexpensive. Easy
setup.
Stock differential
case is usually the
weak point.
Great way to test
the waters to see if
you really want to
upgrade to a full case
locker.
Spicer Parts
Open
Differential
Open
differential
Full case
replacement
None Inexpensive.
Operates smoothly
and seamlessly on
the street.
Poor traction off-
road.
Comes standard in
most Dana axles. Best
used on the street.
