A-TRAC/TRAC/AUTO LSD Explained (Easy to understand, I hope!)

I was talking about an open differential... nothing incorrect about a spinning tire being useless to move the truck... otherwise, you wouldn't have lockers or limited slip added on.

 

I don't have the off road package, so in 4LO would my diagonal tires that were loose spin and the other diagonal tires not turn? Still trying to figure what open differential means ahahahaha I did watch the video in your signature, but still a little

 

So with my truck I would have better traction in 4hi than 4lo if I'm going down a trail that has mud? Unless I do the yellow wire mod

 

Thanks, I guess I'll be doing the yellow wire mod. 4Lo seems almost useless on a non TRD truck

 

The terms make even discussing this almost confusing...

"auto LSD" means what here?

AUTO LSD is a 2WD only mode that give you TRAC (limited slip) without engine output regulation (ie. more power to wheels). Sadly, Toyota also calls 'AUTO LSD' the "TRAC OFF MODE". TRAC is on, but there is no regulation like TRAC normally has in 2WD...

In 4WD High, TRAC is actually the same as AUTO LSD, but on all 4 tires (ie. no engine regulation).

It would have been better if Toyota called TRAC in H4 "AUTO LSD" instead of 'TRAC'.

Now, if your question is about turning off TRAC/ AUTO LSD (for open differentials)... Toyota calls that "VSC OFF MODE" (both VSC and TRAC are off... unless you put the truck into a condition of near doom, then it will come back on to save you)... The only time I would dream of turning this great system off is to cancel the beeper, if it annoys me when having fun off road. Otherwise, in snow, if you need to spin the tires to try and grab fresh bites to get out... then that is the other reason to turn off the traction controls.

 

Firs of all, David K thank you for posting this thread originally. It helped me with my model decision.

That being said, as an example of when I use AUTO LSD in 2wd: I drive a lot of dirt/gravel roads that don't require 4wd in normal conditions, but may induce wheel spin, say when climbing a hill, or driving in a spirited manner while cornering. In those situations I don't want the computer to kill the throttle, so I use AUTO LSD, and things are peachy.

 

Nice!

So you do notice an advantage of AUTO LSD over TRAC in 2WD? Good!

 

Roads that have loose gravel/dirt on top, it makes a huge difference. Otherwise if I am punching the throttle or just accidentally accelerating a bit too hard, or climbing a hill while doing either it will kill the throttle and my forward momentum.

 

We can't have any loss of forward momentum now, can we? !!

 

Definitely not!

 

phenomenal write up with tons of info.... thanks... just wish there were some closer places to Denver w/o haulin up to the mtns everytime... asking for some sand may be to much

 

Thanks... I am a bit of an info-maniac! But, it is just a fun thing to share when you have details that a few others might actually enjoy reading or learning.

The one thing I want new-bees to A-TRAC equipped Tacomas to know, is that there isn't a bunch of button pushing or learning required for the traction controls. Unless you want to 'play' with the 9 different options. I like having fun with my Tacoma!

The standard setting in H2 and H4 is the best and most useful for probably all your driving needs. The only thing you need to activate is the A-TRAC device... by just pushing ONCE, the A-TRAC button the first time you are in L4. The system will automatically be on standby every time you go into L4 from then on. Pushing it again will de-activate it (as if there is ever any reason to not want maximum traction in Low Range 4wd??!!).

A-TRAC (and TRAC) only actually work IF a tire looses traction, so you are normally an open differential (easy steering) truck, when you don't have any traction issues.

TRAC will let the wheel spin a bit before braking that (those) non-traction tires... ie. 'limited slip'.

A-TRAC halts the spin much sooner, and matches that tire's rotation to the opposite tire on that axle... This is why I compare A-TRAC more to lockers than I do to all other limited slip systems which don't come close to matching tire rotation... They just slow down the spinning so more power can be shared with the traction tire.

 

Thanks for breaking this down. Now when I am stuck in the mud in the middle of nowhere I will know where to come home and look to find out what I did wrong

 

If you push the A-TRAC button the first time you use L4, then it will always be on standby (until you push it again, if you ever do).

Just like TRAC in H4, the A-TRAC only works when a tire looses traction, so power transfers to the tire(s) with traction... there isn't anything better to keep you moving!

 

Great information, thanks David K and everyone else who contributed, now I don't need to RTFM. Picked up my '11 4x4 double cab TRD Off Road yesterday and can't wait to start offroading. My first trip will be to try down and back the 60 miles of national seashore on Padre Island, then big bend.

 

Sounds awesome! I wish I was closer to where I can drive the beach! I go about 300 miles to San Felipe, Baja for that!

Just stay in H4, normal TRAC ON mode (don't touch a thing)... and deflate if needed... If you do bury it because you didn't deflate... try the A-TRAC in L4 to climb out... before diiging too much! Best rule is if your truck starts to struggle driving through the sand, stop and let more air out... 15 psi is golden on the stock Rugged Fails.

 

So how do we disable all that garbage for a sport model??

I wanna punch it and go wild!

 

A Sport has no A-TRAC or Rear Locker... You do have TRAC and AUTO LSD in H2 and TRAC in H4... all of which can be shut off by holding in the VSC OFF switch for a few seconds, while stopped.

 

Cause I have heard of some guys disabling thier abs ad vsc on thier sport models with a splice and a switch. But that was only one thread. And I just wanted some verification