How Does AWD Work?

Here's how an all-wheel-drive system works in your car!

AWD is a term used in vehicles that have the ability to transfer power to all four wheels. The transfer of power is often computer controlled, and features a central clutch that allows for a difference between the speed of the front and rear wheels, which suits it best for on-road use. AWD systems also differ from 4WD / 4x4 systems because there is no LO speed transfer case.

Many modern cross-over utility vehicles employ a part time AWD system, known as a "slip and grip" system. If slippage is detected in the front wheels, some torque is sent to the rear wheels. The design and control of the system dictates how much of that power is sent to the secondary axle. Other vehicles have a full time AWD system, which sends even power symmetrically to all four wheels.

In this video, the ATTESA AWD system from a 2006 Infiniti G35X Sedan is taken apart to show what's inside and how it works. Inside consists of a shaft that links the transmission's output to the rear wheels directly, with a chain and electromagnetic clutch linking the prop shaft to transfer power to the front.

Skip to section in the video:
0:00 Introduction
0:56 Overview of the Transfer Case
2:08 The Teardown
4:59 How it Works
8:01 Electromagnetic Clutch Operation

Keep your AWD vehicle well maintained by rotating tires and changing transfer case and transmission oil regularly. You may purchase items for this here:
Gear Oil:
Transmission Oil:
Nissan transmission Fluid:
Hex Sockets for drain plugs:
Snap Ring Removal Tool (Angle Grinder) used in this video:

This is the Camera I use:

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[tiagobelo]

Its impressive how easy it is to understand this man, especially considering the speed at which he speaks, must be some kind of mechanical witchcraft

[robertwilder]

I don't know why, but I smile whenever I see your old toothbrushes. I appreciate your sharing of knowledge. Keep up the good work!

[jimobrien]

I can’t tell if you’re a mechanic or a full on automotive engineer or some mix of the two but you are exceptionally skilled at both explaining and demonstrating the mechanical principles of everything you cover

[frankm]

This is an old school youtube video. No self promotion, like subscribe bullshit. Just straight information, keep it up. love it

[CatarineausArmory]

I have my special snap ring removal tool and I am heading to my neighbors AWD Cadillac to see if this tear down is accurate...

[gbin]

"State-of-the-art snap ring removal tool" lol

[roddydykes]

This guy explains concepts better than any other channel, and sounds like a better engineer than Engineering Explained

[alexovichsky]

Why is this guy not having 2 million subscribers yet, because his videos are worth that much and more.

[geoffdein]

Excellent. That transfer clutch is from a nissan G35X. I used this in a BNR34 getrag box to eliminate the stock electric over hydraulic system with the electronic system. This enables true 2wd or 50/50 awd but enables me to control the centre diff for some magic results. Launch control being one of many tricks. This has allowed my 350Z to become a supercar

[ts]

It’s the subtle touches of humour that make this channel so great

[lewis]

You gotta love this guy. He doesn't beat around the bush, doesn't mince words.

[DavidJWold]

Wow! Mechanical Genius + Expert Communicator + Flawless Editing = Perfect Video!

[triarii_]

Is that your brother's old cardboard?

[CullenCraft]

Dude this video is INCREDIBLE
I google searched for 20 minutes to get a vague ideo of how this worked but you told me so clearly in amazing fashion

[olafzijnbuis]

It is good to realize that both the input and output of the clutch pack are rotating at nearly the same speed when driving only the rear wheels.
The non-driven front wheels drive the clutch pack via the front differential and shaft.
This greatly reduces wear.
Nice video. Much better than expensive and often inaccurate 3D animations.

[coalroller]

One of the most underrated channels. I wish you make it big. 😊

[awongutume]

Did anyone get overwhelmed? I was lost shortly after! This guy is so knowledgeable I wonder how long it took him to learn all this stuff. Good to know there are exceptionally knowledgeable and qualified technical mechanics like this gentleman who are able to explain and demonstrate so simply without skipping a heartbeat. Very impressed. Did I mention how explicit he was during the process? Kudos to you, sir!

[Daniel-zhqz]

Really interesting, thank you!
And the editing is perfect as always.
The video isn't to long or to short 👍🏽

[test]

Love your breakdowns and explanations, i look forward to seeing you put it together one day! :-D

[Bluelightbandit]

02:32 You hit it and it started bleeding.





It's early in the morning and I'm a lil loopy, don't judge me.