TRD Sport LSD questions...

Hey all, today I got my Tacoma after years of waiting. 2013 access cab trd sport.

Real quick, I've looked everywhere and can't get a solid answer...

Is the trd sport is a true lsd or an open diff with brake assist?

And how does the auto lsd operate if it's already an lsd?

Thanks for the help.

 

Not sure on 2nd gen but on 3rd gen its open diff with brake assist called TRAC. I'd assume its the same on 2nd gen.

TRAC pretty much applies the brake to the spinning wheel forcing more power to go to the wheel thats stuck

 

open diff with brake assist in that year.

 

2005-2008 had mechanical lsd. Yours uses the brakes. No additive needed.

 

You guys are awesome, thanks for the replies.

So the only difference between the or and sport is that the or has atrac and a locker, correct? (Traction speaking). The or is also an open diff?

 

The OR has an electronic diff lock.

 

So does the 2nd gen OR have A-TRAC like the 3rd gen or just TRAC?

 

A-TRAC

 

Is your truck 4wd or 2wd? First let me say one thing, if you have 4wd then when you are in 4H you have automatic limited slip both back and front wheels. This apples to both sport and off road. They are not open diff in 4H. This creates tremendous traction in most conditions. The following is a quote that was the first post in a long long thread. The information is excellent and spot on.

Have you wondered about your 2009 or newer Tacoma TRD Off Road 4WD's (USA) with its many drive options or switches/ buttons (VSC Off, A-TRAC) and what they do???

I sure did... and this is my THIRD 4WD Off Road Tacoma (2001 extra cab, 2005 double cab, 2010 double cab)...

The first two had standard 4WD with OPEN differentials (means when you are in stuck or almost in a stuck condition (mud, sand, snow) ONE tire in front and ONE tire in back get power and spins... often helping to bury you deeper! However, the first two also had the LOCKING REAR DIFFERNTIAL... which gave BOTH back tires equal power... This may not help get unstuck unless one of them has traction (on dry or solid ground). Mostly the Rear Locker greatly improved steep hill climbing on rocky roads... in my experience.

Limited Slip Differential (LSD) action means the normal spinning of a tire without traction is controlled or stopped so that the OTHER tire on that axle can get power... This is a great bonus to us off roaders because we need the tires that have traction to work and don't want the other tires (in loose sand/ snow/ mud) to spin and bury us.

LSD (limited slip differential) action can be done inside the differential (with clutches) or at the tires (with brakes). Brakes can be easily replaced as they wear out, but re-building a differential is a bigger issue! Toyota wisely went the brake route for their system.

The system is called 'TRAC' in 2WD* and 4WD High Range. It is called 'A-TRAC' in 4WD Low Range. In 2WD, both brakes and power regulation is utilized. In 4WD, engine output is not regulated.

*Also, in 2WD you can have 'enhanced' LSD with even heavier braking action to the spinning tire with a quick push of the VSC Off switch, which turns on 'AUTO LSD'.
Only in 2WD can you go into AUTO LSD. Since we have 4WD, I would think using it would be even better than AUTO LSD? Perhaps helpful for those with only 2WD.

Toyota also allowed us the CHOICE of having LSD or OPEN differentials... Just in case you want the tires to spin freely (rocking back and forth out of a stuck, or doing doughnuts in a wet field)!

To have open differential(s):

2WD: Normal is TRAC on... Hold the VSC Off switch (the one with the truck and wavey tire lines) down for 3+ seconds, while stopped. VSC, TRAC and AUTO LSD are all off.

H4 (4WD High Range): Normal mode is TRAC on... just like in 2WD. To open the differentials: Hold the VSC Off switch down while stopped for 3+ seconds and TRAC and VSC are turned off.

L4 (4WD Low Range): Normal mode is open differntials.*

*Many of us find it odd that L4 is normally in the open diff. mode... as you would typically only use L4 for the most severe traction situations where LSD would be a benefit.

To activate LSD in L4, push the A-TRAC switch next to the cigerette lighter. Once pushed, A-TRAC will always be on in L4, unless the switch is pushed again.

The Rear Differential Lock is also available in L4 with or without A-TRAC (LSD on the front axle) turned on. With A-TRAC on, one would have maximum traction, however when the rear is locked, A-TRAC only works when the truck is going less than 3 mph. Obviously, Toyota wants us only to use the rear locker for getting unstuck or very slow crawling. VSC, TRAC and ABS are all off in L4, as well.

For typical driving, H2 (TRAC on) and H4 (TRAC on) will do almost everything you would want. In L4, I think you would do better with A-TRAC on... would give you the same traction benefit as when in H4... So, that would be the only switch to activate when four wheeling slow in low range... unless you did get stuck (if that was possible now). In that case, you have the Rear Diff. Locker to activate in L4.

I had the opportunity to test the new truck in deep sand and hill climbs shortly after getting it and was amazed at the improvement over the previous Tacomas' open differentials. The truck in H4 would not get stuck in sand with the tires fully inflated. In the past, lowering pressure to 10-15 psi would have been required. After driving around in H4 (TRAC on), I opened the differentials (TRAC off) and the truck bogged down in the sand (got stuck). I then went into L4, A-TRAC and Locked the Rear Diff. I applied the gas and the truck pulled itself out of the sand! All without getting out of the cab to remove sand from in front of the tires or letting any air out. Once 'on top' of the sand, I switched back into H4 (TRAC on) and drove about easily.

Because the owner's manual was lacking clarity and nobody at my dealership could explain the new systems well, I needed to do this... I did get a lot of help from the people here on Tacoma World helping me understand what I had... and I thank you guys a lot for it!

The list, below itemizes the drive modes... we have nine!

1) 2WD: VSC and TRAC active, engine regulated ('Limited Slip Lite').

2) 2WD: 'AUTO LSD' ('TRAC OFF MODE'). No engine regulation for 'strong' limited slip.

3) 2WD: 'VSC OFF MODE' (TRAC is off for 'open differential').

4) 4WD-Hi: VSC and TRAC active. No engine regulation for 'strong' limited slip.

5) 4WD-Hi: 'VSC OFF MODE' (TRAC is off for 'open differentials').

6) 4WD-Lo: VSC and TRAC are both off in L4 ('open differentials').

7) 4WD-Lo: 'A-TRAC' on gives a 'locker-like, super strong' limited slip, front and rear.

8) 4WD-Lo: Rear Differential Locked and open front differential (A-TRAC off).

9) 4WD-Lo: RR DIFF LOCK + A-TRAC on, 3 MPH limit.

Thanks everyone, and I hope this helps other newbies to understand '09 and '10 Tacomas with TRAC, A-TRAC, AUTO LSD...

 

Get a Detroit trutrac for the rear an have the best limited slip money can buy. With the factory brake assist your truck will be a traction beast..still isn’t quite locker level but it’s the best mod I’ve done.

 

That's all true but it omits the fact that a true mechanical LSD is SO MUCH MORE FUN!!
It biases torque to the wheel with traction which is fundamentally different than applying brake to the wheel with slip.
Why do you think BMW's M series has mechanical LSD? Sure not because BMW didn't already figure out electronic LSD.

I don't need ABS to kick in and brakes applied when I'm trying to go sideways thru a turn!!

 

I would say the BEST is a Torsen
Or Auburn's design that has a mechanical LSD until you hit the switch and turn it into a spool! Not available for Toyotas unfortunately

 

I agree I should have specified for Tacoma. Plus the trutrac doesn’t have springs an clutches that can wear out it’s a helical/worm gear type.

 

Does the above summary apply to 2012-2015? I've had 4wd's for over 40 years and I have to admit I'm more than confused regarding the Tacoma's traction control modes....

 

In addition to A-TRAC and a locker, the OR also has a larger brake booster, different shocks/coil springs, and DAC.

 

I agree mechanical LSD and lockers are awesome, the ultimate, but if you are just an everyday driver who occasionally off roads they would be an unnecessary expensive mod that would seldom if ever be used. Nice to have though.

 

My quote comes from a thread that is over 70 pages long and over 1200 responses. I agree it’s all really confusing. Go to the thread and start at the last page and work your way back 6 to 10 pages. It’s very informative and I think it will clarify things for you.

 

So to get this straight....

In regular 2hi, it operates with an open diff.
In 2hi w/ auto lsd, it operates essentially as an lsd.
In 4hi, it's operating as lsd front and rear.
In 4lo, operates as lsd front and rear.

That correct? I've heard the trd operates with lsd constantly, but the auto lsd is just a stronger version.

Sorry for the questions, this is confusing.

 

I see your point, but the LSD works all the time when it rains up-hill acceleration from a stop greatly enchanted, boat ramps are a cake walk now. So many situations can be thought of where I had issues with it being open an having to use 4wd for the mildest of things the lsd makes it a breeze. May also be driver error but it corrects most of my lack of skill. Plus I got mine from eBay like my bumper for 305 shipped waited for one of their big sales an cashed in some reward points I find it to be very affrodable.
Since it only replaces the carrier I didn’t have to get new gears or shims or anything like that it’s back at factory backlash so no issues this far. Operates just like a normal open diff when around town. The factory brake assit lsd leaves much to be desired.

 

no shims?!? Who installed it for you?
When I installed my Electric Locker (also made by Eaton like your TrueTrac) I found that factory side bearing preload wasn't tight enough so I had to order a ton of Toyota shims to tighten it up while keeping the backlash dialed in.