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Choose the Best Traction-Adding Differential

Posted in How To: Transmission Drivetrain on July 26, 2019
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Contributors: Courtesy of Manufacturers

Selecting 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 possibly 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 differential will operate as seamlessly as a factory open differential. Selectable lockers are a great choice for those who need the traction advantage of a true locking differential while still maintaining streetability for commuting. These lockers can be turned on and off, providing predictable and stable 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, including a 12-volt switch, air pressure, or a cable shifter. Die-hard off-road fanatics will often choose automatic locking differentials or a rear spool for cost savings, simplicity, and reliability, taking in stride any of the handling 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 automatic 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.

Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
Cone-clutch limited slip Full case replacement Automatic Great for front axle applicatio. 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 an even better torque bias.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
Clutch disc limited slip Full case replacement Automatic Factory option in many Dana axles. Nearly seamless operation on street. 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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
Gear-driven limited slip Full case replacement Automatic No clutches to wear out. No special oil required. Internals are somewhat fragile and can break if abused. Aggressive limited slip that's great for snow and ice and mild off-road use in front and rear axles.
Type Case Style Engagement Method Pros Cons Characteristics
Mechanical locking differential Full case replacement Selectable, 12-volt electric engagement Benefits of open differential when unlocked and full locker when locked. 12-volt wire could be vulnerable. Locker unlocks and then locks when changing directions. Engages and disengages quickly. Great choice for front differentials and front and rear in daily driven 4x4s.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
Mechanical locking differential Full case replacement Selectable via external air or manually in an emergency Benefits of open differential when unlocked. Can be manually operated in emergency. Heavy-duty differential cover included. Limited application. Requires air source. Complex wiring. Vulnerable air lines. Engages and disengages quickly. Great choice for front differentials and front and rear applications on daily driven 4x4s.
Type Case Style Engagement Method Pros Cons Characteristics
Mechanical locking differential Full case replacement Selectable via shifter and cable, electric, air, or manually in emergency Benefits of open differential when unlocked. Can be manually operated in emergency. Heavy-duty differential cover included. Heavy shifter cable can be difficult to route and adjust. very limited applications. Heavy shifter cable can be difficult to route and adjust. very limited applications.
Type Case Style Engagement Method Pros Cons Characteristics
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. Limited applications. The automatic locking function can be a bit brutish for some drivers. Best used on 4x4s that spend a lot of time off-road.
Type Case Style Engagement Method Pros Cons Characteristics
Gear-driven limited slip Full case replacement Automatic No clutches to wear out. No special oil required. Internals are somewhat small and could break if abused. Aggressive limited slip that's great for snow and ice and mild off-road use front and rear.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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.
Type Case Style Engagement Method Pros Cons Characteristics
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
866-293-9078
http://www.arbusa.com
Auburn Gear
Auburn, IN
260/925-3200
http://www.Auburngear.com
Eaton
Cleveland, OH
800-386-1911
http://www.eaton.com
G2 Axle & Gear
Compton, CA
310-900-2687
http://www.g2axle.com
OX USA
727-230-7803
http://www.ox-usa.com/
Powertrax
Chicago, IL
864-843-9275
http://www.powertrax.com
Spicer (Dana Aftermarket Group)
Toledo, OH
800-621-8084
http://www.SpicerParts.com
Strange Engineering
Morton Grove, IL
847-663-1701
http://www.strangeengineering.net
Torq-Master Technology (Aussie Locker)
585/723-1489
http://www.aussielocker.com
Yukon Gear & Axle
Everett, WA
888-905-5044
http://www.ringpinion.com

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