Auto LSD / ATrac - Doesn't seem to work

[Grifter7]

Hey Everyone,

I'm sorry if this has been covered already, I tried to search for an answer but didn't find what I was looking for.

I recently bought a 2008 4Runner Limited V8 and am loving it. I had the Toyota dealership replace the transfer case under warranty since the center diff wasn't locking when I bought it. Now that seems to be working correctly.

Now my concern is that the Auto LSD feature isn't working correctly. I've tried every combination of Hi/Low, diff locked/unlocked, 1/2/D, VSC on/off, traction control on/off, tach <= 3500, etc and I can't seem to notice the Auto LSD feature working (The red Auto LSD light never comes on and it seems like my 1 wheel (or 2 if diff is locked) just spin).

To test it the other day I pulled up to a steep incline with about 1 foot of snow on it. I got part way up and would get stuck and the wheels would just spin. In this case I thought that the Auto LSD would kick in and all 4 tires would spin and give me enough traction to climb the hill. If I had traction control on the car would just make awful noises and shake violently as if it were try to brake the tires or something. Is this the Auto LSD trying to work? However when I look out the door when it's doing that my back left wheel isn't spinning. If I disabled traction control it would just spin a few of the tires. I tried disabling VSC by holding the button for 3 seconds and that didn't seem to change anything.

I'm using the term Auto LSD when maybe I should be using ATrac or Trac or something. Not sure.

If any of you guys have any advice as to what I'm doing wrong, or let me know how yours work so that I know if mine is broken and need to speak with Toyota about it. I really appreciate anyone that could give me some advice.

Some of my main questions to summarize are:
1) Does my vehicle have Auto LSD/ATrac (whatever it's called where it electronically simulates Locking front and rear diffs)?
2) When should the red dash "Auto LSD" light come on?
3) How do I use/engage Auto LSD
4) Is the violent shaking/loud noises when traction control is enabled bad for the vehicle, or is that it just doing its thing?

Thanks!

 

[Grifter7]

Any thoughts?

 

[chaz]

might help- Understanding & Using ATRAC II+ - Toyota 120 Platforms Forum http://www.toyota-4runner.org/4th-gen-t4rs/5036-how-does-atrac-work.html

 

[Synister]

Auto LSD only applies to the V6 in its 2WD setting. In order for you to activate the ATRAC feature, I believe you need to be in 4LO, center diff locked and below 5mph for it to activate.

 

[JB.]

Any thoughts?

As mentioned, Auto LSD refers to 2wd.

The term you want is atrac which changed meanings after 2008. It simply refers to the brake actuators pulsing to combat wheel spin which is the shaking and noise you're referring to. On my 05 the dash light is on the left side of the right hand gauge and says VSC/TRAC. I don't pay attention to the light but I believe it comes on anytime either one starts to operate. VSC should be accompanied by a beep.

I'd bet everything is normal. If you test it in an impossible traction situation it's going to seem broken. Try some milder situations where it will engage briefly.