Difference Between Differentials

Difference Between Differentials
October 20, 2015 @ 2:10 pm

 

Open Differential

What It Does
Splits engine torque into two outputs, each of which is able to rotate at a different speed.

Shortcomings
When one tire loses traction, the opposing tire also experiences a torque reduction. In the worst case, your car is stuck with one wheel freely spinning while the tire with better traction can’t deliver enough torque to budge the vehicle. Modern traction-control systems compensate by applying the brakes (and thus a reaction torque) to the slipping wheel. That said, a more sophisticated diff is generally quicker-acting and more effective than this type.

Found In
Anything without the pretense of performance or off-road ability—family sedans, crossovers, minivans, economy cars, etc.

Locking Differential

What It Does
With the diff locked, the connected wheels always spin at equal speeds. In sand, mud, and snow, a locked differential ensures that torque continues to flow to the wheel with higher traction.

Shortcomings
Behaves like an open differential when not locked. Locking the diff on a high-grip surface such as dry pavement makes it difficult to turn the vehicle and can grenade the driveline.

Found In
Jeep WranglerMercedes-Benz G-classRam 2500 Power Wagon; optional on most full-size trucks.

Limited-slip Differential

What It Does
A limited-slip differential marries the concepts of open and locked diffs, working like an open differential the majority of the time, then automatically beginning to lock as slip occurs. Lock-up can be achieved via a viscous fluid, a clutch pack, or a complex geartrain.

Shortcomings
Purely mechanical limited-slip diffs are reactive. That is, they don’t begin to lock up until after wheelslip has occurred.

Found In
Nissan 370Z with Sport package (viscous), Mazda MX-5 Miata (clutch type), Scion FR-S/Subaru BRZ (helical gears).

Original Source: http://blog.caranddriver.com/diff-definitions-each-type-of-automotive-differential-explained/