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

I'm sure its not the first or last time.

 

I wheel with two friends who have lifted Rubicons (locker front and rear) one is on 33's one is on 35's. My truck is on 33's. We have all 3 made it everywhere we have gone thus far. That doesn't mean anything I know but,

Often times they try a section with only the rear locker engaged, when they can not clear it they engage both lockers and have always cleared it.

I use ATRAC and have always cleared the same obstacles. So certainly the argument can be made that at some point they may clear an obstacle that I can't, however we know for a fact that in places where they HAD to have BOTH lockers engaged to make it, I also made it using ATRAC.

This is conclusive evidence that the assistance of ATRAC is at least CLOSE to to that of lockers.

I'm not debating which is best, as I already said ultimately in most situations you would be better off fully locked but who cares? The argument isn't "Should I get ATRAC or get lockers?" The argument is I already HAVE ATRAC, is it going to help me Get most places I would not otherwise get to?

The answer is a undeniable yes.

If you put lockers in your truck, awesome! But don't get all hurt because the stock Tacoma is rolling right along side you.

 

Well said! I am overjoyed that I don't have to spend another $ to get all the traction I need to get to the places I want to go with my STOCK Tacoma (2012 TRD Offroad).

BTW, I like the ride on my stock much nicer on the highway then anything with a bunch of lifts and mods; and I have ridden in several. My fat old butt likes to be comfortable...

 

Thanks for the added positive comment! You understand my purpose of discussing A-TRAC... exactly!

 

Thanks Al... Have fun with your truck!

 

So what was the burning smell? Shame I have to read 2 pages of nothing just to realize that this wasnt answered.

 

Why not send him a PM?

In the 2+ years I have had an A-TRAC Tacoma, there has never been any odd smell, burning or otherwise. I was driving on a 4x4 trail for 3 hours, twice on one weekend and most of that time was in low range (with A-TRAC turned on)... never a problem.

 

Exactly right, A-TRAC is on or 'active', but the braking of any one wheel only happens if and when the wheel looses traction and tries to spin. By braking that spin to the same rotation as the opposite tire on that axle, A-TRAC effectively becomes a 'locker' in that both tires on an axle rotate the same speed. It doesn't stay locked when you don't need it to be, so steering in uneffected! Automatic lockers on the front and rear is a good way to describe the A-TRAC system.

TRAC and AUTO LSD systems only slows down the non traction tire(s) to transfer some energy to the traction tire(s), so they are best described as 'Automatic Limited Slip' systems.

 

Do you live on this web site? Jeeze, I look at it once or twice a day...

Anyway, look at my words and those words say effectively becomes a locker in that wheel rotation is matched across the axle... which is what a locker does... but requires manual operation. A-TRAC is automatic. You know when it works because of the noise it makes (and that you don't get stuck)... During the 3 hour low range trip, I heard it become active dozens of times... I wasn't counting, makes no difference... the Tacoma is unstoppable and I am the most pleased with my 2010 of the three Tacomas I had.

 

I'm not really sure there is anything to argue about in regards to this as there are too many variables to consider. I mean constantly on for 1 minute or intermittently on for 3 hours what is the question or the debate trying to get at?

If your saying at some point under constant use or being "triggered" the brakes will overheat, that is entirely possible, however it doesn't mean anything if it never happens. I'm trying to envision the offroad adventure one would be on where a fully locked vehicle would be required 100% of the trail, and how long that trail would be.

Even the most demanding of trails in the U.S. do not require a fully locked vehicle for 100% of the trails length. Sections, certainly, but I suspect in a large percentage of those trails a fully locked 05+ tacoma wouldn't make it simply because of its design To long/too wide approach/departure angles etc).

Basically I'm suggesting you will never encounter conditions extreme enough over a long enough period of ATRAC activation to overheat the brakes.

So the argument surrounding overheating brakes seems somewhat moot unless I'm missing something or I am grossing under-estimating the amount of time required during activation to overheat the brakes.

Regardless of lockers or not, if your tires are unable to gain traction on the surface they are on (deep soft sand, sand on rock, ice etc), you are not going anywhere. So if you were just sitting there giving it gas and not moving, allowing the ATRAC to cycle needlessly, then I suppose you could overheat the brakes, but that is less of a ATRAC problem than it is an operator error. Yes? No? Maybe?

 

here i am at the legendary HAMMERS..."home of the most demanding race in the world" King Of The Hammers or simply known as KOH..

this particular trail is called Claw Hammer..refereed as one of the easier trails of the HAMMERS trail system..once on it i had to remain locked in the rear 100% of the time and locked in the front about 70% of the time...i wouldnt make it past the first rock without being locked. the trail is only a few miles long but it took us 3-4 hours to get through..





i know there's a few trails on the east coast that are the same way as well..once your're on it, you must remain locked to get through

 

I'll second that emotion.

BTW, I still don't know shit about A-TRAC, nor do I want to.

 

thanks for the rep

here's another pic from a trail called Odessa at Calico Ghost town..another trail that you should remain locked in the rear for the length of the trail. first time i did this trail it literally took us around 4 hours to complete..we were noobs back then and had no idea what we were getting ourselves into, now it takes us 45 minutes or less due to our experience level, 35" tires and added front lockers, and better suspension...funny enough though..my buddy denny in his 2008 sport and mechanical LSD had a easier time (wasnt pretty at all) then my buddy brian and his FJ that was locked in the rear and with ATRAC..denny has since added ARB lockers front and rear.




first of many tugs that day


buddy's FJ


break time

 

Great pictures and a very fun place to spend a nice long weekend, except when the weather is in the teens...

 

That supports what I said. In your own example of a tough trail you didn't need to be fully locked but only 70% of the time.

Certainly you would not have made the trail without the lockers no argument, just saying you didn't need to be fully locked 100% of the trail.

I have not been out there in over a year and never with my Tacoma. But its going out this year. I think my 33's would be far more of a limiting factor than lockers or ATRAC wouldn't you say?

 

still dont see what your point is..not trying to be an ass..i just dont know

in my opinion and experience..i'll take 33" tires and a rear locker only.. over a rig that has 35" tires, rear locker and ATRAC. ATRAC will only hamper my momentum and progress on the trails in difficulty that i like to do.

 

We can slice and dice it any number of ways really. I guess we all just have different experiences and likely for different reasons that we would never be able to address properly on a internet forum.

See ya on the trails

 

Meh....give me a taco 2008 and below and ill be happy