4 Wheel & Off Road – November 2019

4WHEELOFFROAD.COM 4-WHEEL & OFF-ROADNOVEMBER 2019 17

DIFFERENTIAL TYPE CASE STYLE ENGAGEMENT METHOD PROS CONS CHARACTERISTICS

Powertrax

Lock

Right

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.

Strange

Engineering

Spool

Spool Full case

replacement

Always locked Inexpensive.

Simple, bulletproof

traction.

Not at all ideal

on-road. Tires

chirp when

cornering. Hard

on axleshafts and

other drivetrain

components.

Best used in the

rearend of 4x4s that

spend most of their

time off-road. Not for

front applications

where steering is

important.

USA Standard

Gear

Spartan

Locker

Mechanical

locking

differential

Drop in stock

case

Automatic Inexpensive. Easy

setup.

Stock differential

case is usually the

weak point. Tire

size limitations.

Great way to test

the waters to see if

you really want to

upgrade to a full case

locker.

Yukon Dura Grip

Positraction

Clutch disc

limited slip

Full case

replacement

Automatic Nearly seamless

operation on the

street. Great for

on-road snow and

ice. Can be rebuilt

at home.

Provides

marginally better

traction than an

open differential.

Requires friction

modifier in oil.

Clutches wear out.

Best used on the

street and very mild

off-road applications.

Yukon Grizzly

Locker

Mechanical

locking

differential

Full case

replacement

Automatic Simple. No wires,

no air lines,

no switches,

no special oil

required.

Can cause on-road

handling quirks

and does not play

well with ABS and

other sensors

found on newer

4x4s.

Automatic locking

function can be a

bit brutish for some

drivers. Best used on

4x4s that spend a lot

of time off-road.

Yukon Mini

Spool

Spool Drop in stock

case

Always locked Very inexpensive.

Simple, easy

setup.

Very limited

applications.

Stock differential

case is usually the

weak point.

Best used in the

rearend of 4x4s that

spend most of their

time off-road. Not for

front applications

where steering is

important.

Yukon Spool Spool Full case

replacement

Always locked Inexpensive.

Simple, bulletproof

traction.

Not at all ideal

on-road. Tires

chirp when

cornering. Hard

on axleshafts and

other drivetrain

components.

Best used in the

rearend of 4x4s that

spend most of their

time off-road. Not for

front applications

where steering is

important.

Yukon Zip Locker Mechanical

locking

differential

Full case

replacement

Selectable, internal air

engagement

Benefits of open

differential when

unlocked.

Requires air

source. Air lines

are fragile. Internal

air leaks will case

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.

SOURCES

ARB

866.293.

arbusa.com

AUBURN GEAR

260.925.

auburngear.com

EATON

800.328.

eaton.com

G2 AXLE & GEAR

310.900.

g2axle.com

OX USA

727.230.

ox-usa.com

POWERTRAX

800.934.

powertrax.com

SPICER PARTS

800.621.

spicerparts.com

STRANGE ENGINEERING

847.663.

strangeengineering.net

TORQ-MASTERS

585.723.

torqmasters.com

USA STANDARD GEAR

usastandardgear.com

YUKON GEAR & AXLE

888.905.

yukongear.com