Limited Slip Differential

Limited Slip Differential (LSD): Why your vehicle needs it?

What is Limited Slip Differential (LSD)?

Firstly, know here what a differential is and how it works? The manufacturers offer the differential mechanism for better handling of the vehicle. However, it doesn’t offer high mechanical efficiency because of its ability of slippage. At times, a high amount of friction is also necessary. So, the engineers developed the limited slip differential or LSD.

However, a low-friction differential on a high powered vehicle can reduce the traction over the slippery surfaces. Besides, during acceleration, the higher torque of the engine causes excessive wheel spinning on uneven surfaces. This also causes lifting of the left side wheel off the ground.

How a Limited Slip Differential Works?

By increasing the friction between the sun wheel and the differential cage opposes the differential action. Thus, the differential does not slip and sends the drive equally to both the wheels. The manufacturers term this technology as the LSDs. Hence, some of the modern cars employ the Limited Slip Differential.

Characteristics of the Limited Slip Differential

The LSD is similar to the conventional differential. However, it transmits only a part of the torque from the ring-gear though clutch-packs between the side gears and differential case. In the case of wheel slippage, it activates the clutch-pack opposite to the slipping side. It does so by separating the forces between the pinion mate and the corresponding side gear. This increases the torque delivered to the non-slipping wheel. So, the wheel begins to move. It is vital to see that with unequal traction, both wheels slip. That means, the LSD did its job.

Limited Slip Differential Components:

The Limited Slip Differential consists of multi-disc clutch-pack that sits behind the sun wheel. The inner and outer plates are splined to the sun and cage wheels respectively. Some manufacturers offer the automatic version of the limited slip differential.

Limited Slip Differential (LSD) (Courtesy: Eaton)
Limited Slip Differential (LSD) (Courtesy: Eaton)

The rear axle has unique features of unitized bearings and LSD. The unitized bearings are pre-set. Besides, they do not require any adjustments. The lubrication is through the differential lube. So, it does not require the draining of axle lube to service the bearing or seal of the hub.

The LSD comes with a self-locking mechanism. Manufacturers use custom trade names for the LSD to market their products. These include Trac-Aide, Power-lok, Sure-grip, Positive-Traction, Anti-spin, and Spin-resistant etc. Dana, Eaton, and ZF are some of the leading manufacturers of the LSDs in the world.

Note: All Images - Courtesy Eaton

Watch the Limited Slip Differential (LSD) in action:

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