How exactly does auto LSD work?

  1. Welcome to Toyota Tundra Forums : Tundra Solutions Forums – General discussion forum for Toyota Trucks

    Welcome to Toyota Tundra Forums : Tundra Solutions Forums - a website dedicated to all things Toyota Tundra.

    You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, Join Toyota Tundra Forums : Tundra Solutions Forums today!
     
Results 1 to 10 of 10

Thread: How exactly does auto LSD work?

  1. #1
    Junior Member
    Join Date
    Sep 2005
    Location
    Lynnwood, WA
    Posts
    117
    Liked
    0 times
    Rep Power
    10

    Angry How exactly does auto LSD work?

    I was trying to back up a friends driveway today and got my right rear tire over in the gravel. The left rear was on concrete. I tried to keep going and the right rear started digging it's way to china. I could hear the abs unit ratcheting and the computer was pulling engine power. Is this the situation that you would push the auto LSD button and if so what would happen? Would the abs unit clamp down on the spinning tire so the other one would pull me up the hill? I ended up pulling forward and getting both on the concrete. After I got up the hill it dawned on me that I could have just thrown it in 4WD for a few feet. This was in my brand new and I mean "brand new" (47 miles) 2006 DC limited Tundra.

  2. Remove Advertisements
    Toyota Tundra Forum
    Advertisements
     

  3. #2
    Supporter JustBNme's Avatar
    Join Date
    Jul 2006
    Location
    New Orleans metro area
    Posts
    369
    Liked
    1 times
    Rep Power
    9

    Default Re: How exactly does auto LSD work?

    From my understanding re: our LSDs, engaging it under the conditions you described would've worked, by transferring torque to the wheel that still had a grip on the pavement. The only part I'm not all that clear about is the "Auto" part in calling it Auto-LSD, since you have to enable it when you need it (and the Manual says keep it off when not in use).

    Others may have better references, but I found the description of various differentials over at HowStuffWorks rather informative.

  4. #3
    Veteran Member
    Join Date
    Oct 2005
    Location
    TundraSolutions.com
    Posts
    780
    Liked
    1 times
    Rep Power
    10

    Default Re: How exactly does auto LSD work?

    The Auto LSD achieves the equivalent functions of an LSD (Limited Slip Differential) through the use of a traction control system. For this reason, the contents of brake control are the same between Auto LSD and
    TRAC. When the driver presses the Auto LSD switch, this system achieves the LSD effect by regulating the hydraulic pressure that acts on the drive wheels and controlling the engine output in accordance with
    the amount of pedal effort applied on the accelerator.

    TRAC enhances the startoff performance of the vehicle during low-resistance surface conditions, such as snow or mud, by restricting the acceleration effort during a startoff, in order to prevent the wheels from spinning.

    On the other hand, Auto LSD tends to enhance the acceleration effort somewhat, in order to apply greater drive torque to the wheel that is making contact with the ground. Thus, this function enables the vehicle to get unstuck if a wheel loses its grip, and enhances the vehicle’s startoff performance on high-resistance surface conditions such as gravel roads.

    Precautions for Operating the Auto LSD:
     Operate the Auto LSD control only when the wheels are susceptible to spinning, such as when driving on a grooved, slippery, or rough surface.
     Make sure the vehicle is stopped before turning ON the Auto LSD function.
     To prevent unstable driving conditions, do not continue driving the vehicle with the Auto LSD function turned ON.
     The following conditions must be met to operate the Auto LSD system.
    Auto LSD indicator light turns on when the operation enables.

    i) With the vehicle stopped, the Auto LSD switch has been pressed.
    (Auto LSD system operates by pushing the Auto LSD switch. Vehicle must be stopped to turn on the system. It is possible to turn off the system even if the vehicle is not stopped.)
    ii) The transfer unit is in the 2WD mode.
    iii) The accelerator pedal has been pressed and the vehicle is accelerating.
    (The system is prohibited so as not to prevent the braking operation when depressing the brake pedal.)

     The slip indicator on the combination meter panel will blink when the Auto LSD function is operating.
     If the brake control of the Auto LSD is operated continuously, the temperature of the actuator in the hydraulic brake booster will rise.
    The skid control ECU, which monitors* the temperature of the brake actuator, alerts the driver by sounding the buzzer intermittently if the brake actuator becomes overheated. In this case, the Auto LSD will momentarily stop its operation in order to protect the system.

    *: Skid control ECU calculates the temperature of the brake actuator depend on the energizing time.

     The Auto LSD applies brakes to the drive wheels, and controls the extent of the brake application in order to achieve the function of an LSD. However, it might not be able to achieve this function on a steep incline or on an extremely slippery surface, such as a frozen snow surface.

  5. #4
    Junior Member
    Join Date
    Sep 2005
    Location
    Lynnwood, WA
    Posts
    117
    Liked
    0 times
    Rep Power
    10
    Thread Starter

    Default Re: How exactly does auto LSD work?

    Well that pretty much tells me what I needed to know. Thank you. Sounds like I should have stopped, pushed the LSD button and it should have walked right up the hill.

  6. #5
    Supporter JustBNme's Avatar
    Join Date
    Jul 2006
    Location
    New Orleans metro area
    Posts
    369
    Liked
    1 times
    Rep Power
    9

    Default Re: How exactly does auto LSD work?

    Great detail in that reply. That's how I like to learn!

  7. #6
    Veteran Member
    Join Date
    Oct 2005
    Location
    TundraSolutions.com
    Posts
    780
    Liked
    1 times
    Rep Power
    10

    Default Re: How exactly does auto LSD work?

    Quote Originally Posted by JustBNme View Post
    Great detail in that reply. That's how I like to learn!
    Complete information can be found in the 2004 Toyota Tundra New Car Features

  8. #7
    Rookie
    Join Date
    Sep 2006
    Location
    Bellevue, wa
    Posts
    5
    Liked
    0 times
    Rep Power
    0

    Default Re: How exactly does auto LSD work?

    I have a 2000 limited TRD Tundra. I've read alot of things were its said that LSD was made optional in 02. I'm pretty my 00 has it though, when I slip the wheels on hills and corners occasionally, it feels like I have a posy rear-end. My dealership parts department even ran my vin to see if I did an appearently I do. So whats the deal with all these websites saying i dont?

  9. #8
    Junior Member
    Join Date
    Jun 2004
    Location
    Middle GA
    Age
    36
    Posts
    374
    Liked
    0 times
    Images
    10
    Rep Power
    18

    Default Re: How exactly does auto LSD work?

    I don't think there was an electronic "auto" LSD back then. You probably have a real mechanical LSD, which was probably an option, just like keyless remote entry, etc. If you do have a mechanical LSD, there is probably a sticker on your rear diff for LSD lube only.

    EDIT: Oh, I just realized you were saying you were told that the LSD didn't become an option UNTIL 02. In that case I don't know what I'm talking about... oh well.

  10. #9
    Junior Member CT-Tundra's Avatar
    Join Date
    Oct 2005
    Location
    CT
    Posts
    225
    Liked
    0 times
    Rep Power
    10

    Default Re: How exactly does auto LSD work?

    This is an EXCELLENT piece of reference for differentials that shold answer all your questions:

    Howstuffworks "How Differentials Work"
    2005 Tundra Access Cab 4x4 4.7L - BFG ATs on MT Classic Locks - Warn M8000

  11. #10
    Rookie
    Join Date
    Sep 2006
    Location
    Bellevue, wa
    Posts
    5
    Liked
    0 times
    Rep Power
    0

    Default Re: How exactly does auto LSD work?

    mkay cool, well i dont have the sticker, my buddys 02 TRD does so i know what it looks like, very interesting....i guess maybe i could lift my rear end up and see which way the wheels spin...? i will also check out that howstuffworks site. i must have a mechanical one then cuz it definantly has that locker feeling when i start slipping but when I roll around town I hear and feel nothing. I had a old 84 toyo 4X4 with Detroit's front and rear and you can always hear them click around turns cuz they were disangaging. The one my Tundra must be factory or at least a good aftermarket....thanks for the tips!

LinkBacks (?)

  1. 09-02-2014, 05:04 AM
  2. 05-14-2014, 07:05 PM
  3. 05-13-2014, 04:52 PM
  4. 07-18-2013, 02:45 PM
  5. 12-03-2012, 03:13 PM
  6. 10-08-2012, 01:23 AM
  7. 04-22-2012, 09:56 AM
  8. 01-31-2012, 02:25 AM
  9. 01-04-2012, 09:31 PM
  10. 07-04-2011, 07:51 AM
  11. 02-02-2010, 09:12 AM
  12. 03-04-2009, 11:45 PM
  13. 02-10-2009, 02:07 PM
  14. 11-29-2008, 03:55 PM
  15. 02-29-2008, 12:10 PM
  16. 01-20-2008, 01:28 AM
  17. 01-20-2008, 12:33 AM

Similar Threads

  1. Replies: 0
    Last Post: 07-22-2006, 03:58 AM
  2. Auto LSD vs. Std LSD
    By SuperBusa in forum Tacoma
    Replies: 14
    Last Post: 08-10-2005, 10:07 AM
  3. '05 Tacoma auto trans. approx life
    By vic_ny in forum Tacoma
    Replies: 1
    Last Post: 01-08-2005, 05:09 PM
  4. 03 lsd vs trd lsd
    By r80255 in forum T-Case, Driveshaft, Diff, Axle, Hub
    Replies: 2
    Last Post: 04-19-2003, 05:08 PM
  5. Replies: 0
    Last Post: 03-28-2002, 01:22 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •