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jerem0621's avatar
jerem0621
Explorer II
Aug 05, 2017

How a differential works

I stumble on these old videos from time to time. I thought this on was neat because it explains in a simple way how a rear differential works.

YouTube Video

Thanks!

Jeremiah
  • wnjj's avatar
    wnjj
    Explorer II
    DSteiner51 wrote:
    Yet you will read it here that a 2 wheel drive is in reality only one wheel drives. Watch even after this demo some will still insist on it.


    I guess it depends on how you define 2 wheel drive.

    Applying torque to both wheels isn't the same as applying power to both. With one wheel spinning in the air, some power is applied to that wheel while the equal torque applied to the grounded wheel is insufficient to move the wheel and therefore consumes no power. I would describe that situation as one wheel "driven."
  • It sure looks like one wheel drive when the wheel in the mud spins and the wheel on dry pavement does nothing. Yes they both get the same torque. However there is no work done when there is no motion. The wheel in motion is doing the work and the vehicle does not move.
  • You are correct that both wheels are driven, but folks don't need to describe the whole differential in detail to explain why they are stuck in the mud with one wheel while the other is on dry pavement. To use this example, for all practical purposes, there is no wheel drive.
  • Lynnmor wrote:
    DSteiner51 wrote:
    Yet you will read it here that a 2 wheel drive is in reality only one wheel drives. Watch even after this demo some will still insist on it.


    I wonder why they make limited slip differentials if that is not the case.


    If you can't figure it out after watching the demo then all the facts won't change your mind. I won't waste my time.
  • If open differential it is two wheel drive both getting the same amount of torque. Just because one wheel doesn't have enough traction for the amount of torque the other still gets the same amount. Limited slip or locking axles allows one axle to accept more torque then the other. No matter, both are in fact two wheel drive.

    No matter how many demos or facts are presented there are always those who are so much more intelligent then the engineers when in fact they are ignorant. Years ago I would demonstrate using an actual differential and still folks would deny. Thanks for your public display.
  • DSteiner51 wrote:
    Yet you will read it here that a 2 wheel drive is in reality only one wheel drives. Watch even after this demo some will still insist on it.


    I wonder why they make limited slip differentials if that is not the case.
  • DSteiner51 wrote:
    Yet you will read it here that a 2 wheel drive is in reality only one wheel drives. Watch even after this demo some will still insist on it.


    It's 2WD until a wheel spins with an open diff, then it's one WD!
  • Yet you will read it here that a 2 wheel drive is in reality only one wheel drives. Watch even after this demo some will still insist on it.
  • Cool. I was fascinated by that as a young boy and it kinda drove me nuts until I saw how it worked.