Car Tech 101: Limited-slip differentials explained
3:52

Car Tech 101: Limited-slip differentials explained

Auto Tech
[MUSIC] If two wheels are locked on an axle so that they are not free to turn separately, one or the other has to slide. So engineers had to find a way to connect both rear wheels to the end, without sliding and slipping on turns. The device which makes this possible is a part of the rear axle. It is called the differential because it can drive the rear wheels at different speeds. Now before we talk about limited slip differentials, let's get a quick refresher on differentials. Here's one out of a vintage Alfa Romeo, good because it's fairly simple and can get us down on the basics. The idea behind a differential is to allow the two, in this case rear drive wheels, to turn at different speeds while going in the same direction. That's important in, let's say, turning a corner. Where the outside wheel is going to cover more distance in the same time than the inside wheel. It has to turn faster. If it didn't do that, either the inside wheel would have to slip, or, these gears in the middle would take a beating. A differential allows these two to operate somewhat independently. Power comes in here, from the car's drive shaft here, turns this, which operates a pinion gear, that turns the ring gear, which turns planetary gears, which then turns bevel drive gears, that turn the axles of the output shafts. Now here's where this whole assembly falls down, as miraculous as it is. If one of these wheels loses traction, the power, or the torque, goes to the path of least resistance and spins that wheel, the one that's not getting any grip, while the one that does have grip, since they're getting very little or no power, that's just not a good thing. So whether your car is slipping a wheel because of a poor surface, or because of lifting during cornering, or just because you're standing on it and one wheel's lighting up, a standard or open differential tends to put the power in the wrong place when there's a lack of grip. That's where a limited slip differential comes in. It limits the slip that is natural to a basic differential. If a drive wheel loses traction, the differential sends power to the opposite wheel or axle with the best grip, or the slower moving wheel or axle. Now front-wheel drives have this same function, but it's built into their transaxle, transmission assembly in the front of the car. Now, we could spend hours on the details of how these work internally, but basically there are several types. Geared differentials use spring loading and a more complex pack of gears than a standard or open differential like we have here. Clutch or plate limited slip differentials use those kinds of parts to engage one output shaft or the other based on wheel resistance. If a wheel spins, its clutch or pressure plates loosen to send it less torque. Viscous coupled limited slip differentials rely on discs in the differential spinning in silicone fluid that gets either grabbier or less so based on that friction of spinning. And electronic limited slip differentials are controlled by the car's computer. It reads wheel slip, and then commands clutches electronically to tighten or ease up their engagement on one wheel or the other. And within those four major methods of doing limited slip, there's also another layer. Some that will sense torque, and others will sense wheel speed to make their decision about what to alter. So now you know, when you get a car that has a limited slip differential. It's got some kind of technology built into this power split device that allows it to sense when a wheel's lost traction and send more power or torque to the one that has it. It helps you with performance, traction, and safety. [MUSIC]

Up Next

Is It Time to Finally Buy an Electric Car Under the New Tax Credit Rules?
ev-credits-00-08-35-16-still170

Up Next

Is It Time to Finally Buy an Electric Car Under the New Tax Credit Rules?

Would a Solar Car Change Your Life?
solar-evs-00-05-39-10-still164

Would a Solar Car Change Your Life?

Why So Many People Are Interested in the New DeLorean Electric Sports Car
dal500034

Why So Many People Are Interested in the New DeLorean Electric Sports Car

US Road Fatalities Spike After Years of Progress
euro-ncap-pedestrian-safety-euro-ncap-mp4-00-01-29-17-still001

US Road Fatalities Spike After Years of Progress

Auto Giant Magna Prepares to Make Every Part of a Car Light Up
magna-lighting-00-01-55-05-still131

Auto Giant Magna Prepares to Make Every Part of a Car Light Up

The Best Place to Own an Electric Car
best-states-to-own-an-ev-00-15-12-06-still129

The Best Place to Own an Electric Car

The Full Cost Advantage of an Electric Car Is More Than Cheap Fuel
ev-total-cost-of-ownership-00-02-51-08-still112

The Full Cost Advantage of an Electric Car Is More Than Cheap Fuel

How Will We Deal With a Mountain of Old EV Batteries?
ev-battery-recycling-00-06-10-03-still099

How Will We Deal With a Mountain of Old EV Batteries?

How an EV Works
how-evs-work-00-04-48-14-still089

How an EV Works

Tech Shows

The Apple Core
apple-core-w

The Apple Core

Alphabet City
alphabet-city-w

Alphabet City

CNET Top 5
cnet-top-5-w

CNET Top 5

The Daily Charge
dc-site-1color-logo.png

The Daily Charge

What the Future
what-the-future-w

What the Future

Tech Today
tech-today-w

Tech Today

Latest News All latest news

Ride1Up's 700 Series E-Bike Review: It Replaced My Car
220815-yt-ride1up-700-series-ebike-review-site-1

Ride1Up's 700 Series E-Bike Review: It Replaced My Car

The Apple Watch Has Life-Saving Features
220811-yt-the-apple-watch-saved-my-life-and-could-save-yours-too-site-1

The Apple Watch Has Life-Saving Features

How a Massive Particle Accelerator Could Rewrite the History of the Printing Press
yt-x-ray-scanning-v4

How a Massive Particle Accelerator Could Rewrite the History of the Printing Press

Is It Time to Finally Buy an Electric Car Under the New Tax Credit Rules?
ev-credits-00-08-35-16-still170

Is It Time to Finally Buy an Electric Car Under the New Tax Credit Rules?

Galaxy Watch 5: My First 2 Days With Samsung's Watches
watch-5-thumb

Galaxy Watch 5: My First 2 Days With Samsung's Watches

When Is the iPhone Flip Going to Come Out?
apple-stuff-ep-8cnet

When Is the iPhone Flip Going to Come Out?

Most Popular All most popular

Top 5 iPhone 14 Rumors
iphone14-rumors2021-200000

Top 5 iPhone 14 Rumors

Is It Time to Finally Buy an Electric Car Under the New Tax Credit Rules?
ev-credits-00-08-35-16-still170

Is It Time to Finally Buy an Electric Car Under the New Tax Credit Rules?

Ride1Up's 700 Series E-Bike Review: It Replaced My Car
220815-yt-ride1up-700-series-ebike-review-site-1

Ride1Up's 700 Series E-Bike Review: It Replaced My Car

How a Massive Particle Accelerator Could Rewrite the History of the Printing Press
yt-x-ray-scanning-v4

How a Massive Particle Accelerator Could Rewrite the History of the Printing Press

The Apple Watch Has Life-Saving Features
220811-yt-the-apple-watch-saved-my-life-and-could-save-yours-too-site-1

The Apple Watch Has Life-Saving Features

When Is the iPhone Flip Going to Come Out?
apple-stuff-ep-8cnet

When Is the iPhone Flip Going to Come Out?

Latest Products All latest products

Galaxy Watch 5: My First 2 Days With Samsung's Watches
watch-5-thumb

Galaxy Watch 5: My First 2 Days With Samsung's Watches

Samsung Galaxy Z Flip 4 and Z Flip 3 Specs Compared
220809-yt-galaxy-z-flip-4-vs-z-flip-3-v2

Samsung Galaxy Z Flip 4 and Z Flip 3 Specs Compared

Samsung Galaxy Z Fold 4 First Take: Bigger Cover Screen, New Cameras
jje-9771

Samsung Galaxy Z Fold 4 First Take: Bigger Cover Screen, New Cameras

MacOS Ventura Public Beta: The 3 Best New Features
thumb1

MacOS Ventura Public Beta: The 3 Best New Features

What You Should Know About the Nothing Phone 1
nothingphone1-cms

What You Should Know About the Nothing Phone 1

New WatchOS 9 Features Coming Soon to Apple Watch
p1050672

New WatchOS 9 Features Coming Soon to Apple Watch

Latest How To All how to videos

How to Clean Your Keyboard's Sticky Keys
3keyboards

How to Clean Your Keyboard's Sticky Keys

How to Play Games from PlayStation Plus on PC
psstill

How to Play Games from PlayStation Plus on PC

How to Delete or Disable Your Instagram Account
phoneonorange

How to Delete or Disable Your Instagram Account

Fix Your iPhone Screen With Apple's Self-Service Repair Kit
dsc00641

Fix Your iPhone Screen With Apple's Self-Service Repair Kit

How to Buy a Budget Laptop in 2022
budgetlaptops-00-08-35-15-still001

How to Buy a Budget Laptop in 2022

Google Pay: How to Set Up and Use
googlepay-inhand

Google Pay: How to Set Up and Use