Limited slip diff

A limited slip diff is a huge improvement on an open diff because it works as follows: Inside the diff housing is a set of coil springs (or sometimes a leaf spring as shown here) that pushes the sun gears to the side of the housing. Between the housing and the sun gears are clutch plates that push back and cause friction.

Just like an open diff, the differential gears lie stationary when driving straight ahead, but as you turn, the friction of the clutch plates cause the differential gears to not rotate too easily in their own direction and each side shaft therefore get some of the engine power. The wheel on the ground will receive a percentage of the power (around 25%), while the wheel dangling in the air will still get the majority and turn uselessly. It’s not a perfect solution, but it’s far better than an open diff.

The problem with a limited slip diff is that the friction causes the clutch plates to wear out after a few thousand kilometres. Then a limited slip diff reverts back to a regular open diff until you repair or replace it.

You can install a limited slip diff on the front or rear axle, but it will last longest on the rear axle, and a front limited slip diff may also encumber steering performance.