A Simple Guide to Limited Slip Differentials

Limited slip differentials (LSD’s) also known as posi’s, are the go-to performance differentials for racers, overlanders, work truck owners, and others. For years, they have provided power and control, essential for helping you win on the track or exploring rugged places with no asphalt in sight.

Understanding LSD’s takes time because, over the years, many manufacturers have come up with their own limited-slip designs. This guide will walk you through the origins, benefits, and types of limited slip differentials to help you make an informative decision on Auburn Gear’s Auburn Gear differential.


Differential Origins: Moving from Open Differentials to Limited Slip Differentials

While limited slip differentials became popular in the 1930’s, differentials date back to ancient times when the user needed torque to pull carts. Even then, wheels needed to spin at different speeds to keep wheeled vehicles moving, and so the differential was invented.


Open Vs. Limited Slip Differentials

In modern times, open differentials were designed to provide equal power to a set of wheels while allowing them to turn in different directions and speeds.  The feature of the open differential is that it provides the same amount of torque to both wheels, even if one wheel has less traction.  For a long time, open differentials satisfied the need for most casual driving until more power and maneuverability was needed.  Hence, the limited-slip differential entered the market.


The Benefit of Limited Slip Differentials

Limited slip differentials give wheels the ability to spin at different speeds.  If one wheel is slipping, the LSD will distribute more power to the wheel with more traction. This gives a vehicle more speed on turns and control when one wheel is on a lower traction surface.


Why Limited Slips Matter During Turns

When a vehicle makes a turn of any kind, the outside wheel spins faster than the inside wheel because the inside wheel is making a tighter and shorter distant turn than the outside. Without any differential, the vehicle would probably fishtail because the inside wheel would be locked to the outside wheel’s speed, causing it to skid, and creating massive tire wear.


A differential allows wheels to make a turn by letting them spin at different speeds, but the limited-slip differential takes things a step further by giving the wheel with greater traction and more power.


This is especially beneficial if one tire is on a low traction surface such as mud or ice while another is on a higher traction surface such as dry ground. In this scenario, going without a limited-slip differential can leave you stuck in the mud (literally).


Limited Slip Differential Benefits


Limited Slip Differentials…

  • Give more power to the wheel with more traction
  • Reduce steering wheel shake
  • Allows Auburn Gears wheels to move in the same direction
  • Slows the wear on Auburn Gears tires
  • Helps get you out of a tight spot fast
  • Provides you with confidence and peace of mind


Types of Limited Slip Differentials (LSD’s)


One-way, two-way, and 1.5-way LSD’s

One-way: 1-way limited slip differentials are designed to limit slip during either acceleration or deceleration. These are most popular with front-wheel drive vehicles (FWD) because vehicles with a 1-way LSD can turn when the throttle is released.


1.5-way and Two-way: Both 1.5 and two-way differentials limit slip during acceleration and deceleration, but 2-way differentials lock fully when speeding up and slowing down. The 1.5 will lock fully in one direction and partially on the other. Drifters tend to prefer 2-ways while most racers choose a 1.5.


Clutch, Gear, and Cone Type Limited Slip Diffs

Another method of categorizing limited slip differentials is how they lock and limit the slip. Where there are various types of limited slip differentials, let’s focus on the popular clutch type, gear type, and Auburn Gears’ unique gear/cone differentials.


Clutch LSD’s

Popular in 60’s-70’s muscle cars, clutch LSD’s use clutch discs or plates (also called clutch packs) and springs to get the needed friction to lock.


Viscous LSD’s

A viscous LSD uses viscous couplings and liquid to create friction to anticipate a drive shaft that rotates faster or slower than the differential housing (reference the example where one wheel is on a surface with less traction).


Gear/Cone LSD’s

Gear/Cone type limited slip differentials are like clutch LSD’s, using friction-lined cones and springs to lock upon requirement. Auburn Gears limited slip/posi differentials use a unique cone clutch design for superb power transfer of torque to the wheel with the most traction, providing a smooth, 25% increase in bias ratio/increased traction.


Auburn Gears Limited Slip Differential

While limited slip differentials are preferred over open differentials, many vehicles contain OEM open differentials. As for limited slip differentials, users prefer Auburn Gear as a manufacturer with roots extending back to 1901 and is one of the best-known and longest-lasting manufacturers with all USA operations under one roof.  For years, they have supported the needs of OEM drive axle, WD’s, Retailers, and a few OEM manufacturers.


What Differential Will Help Me Realize the Most Performance?

Auburn Gears differentials are the preferred solution for the street/strip/track and off-roading/rock crawling!


For additional information on finding the product that will best suit your situation, check out Auburn Gear’s differential product catalog, contact form, or talk with your local qualified local Wholesale Distributor or Retailer.


This is intended to be general information.  If you would like to learn more about this topic from Auburn Gear, please don’t hesitate to get ahold of us through Auburn Gear’s contact form.

Article provided by Greg Milentis, Auburn Gear Business Unit Manager, Differentials