Hey guys, done a lot of reading on here, some great info! I’m in the market for a new vehicle soon and it’s boiled down to either a 2010 Silverado or a 2010 4runner. I’ve always loved 4runners, but was disappointed to find out that the new SR5s are not available with a rear locker. I know the Trail Edition has a locker, but a Trail edition is overkill for me, and is not available with a 3rd row. I won’t be doing any true offroading, and snow/ice is not really a concern in this part of Texas.

My concern is with the 4wd SR5’s ability on sand. In the summer we take trips down to the Texas coast for vacation and fishing. I’ve always rode down in 4wd Chevrolet trucks, we’ve never had any problems getting around to some of the more remote fishing spots. The 4wd trucks have the automatic locking rear end (g80) and don’t have any problems in the deep sand or dunes. There are some steep sand dune/hills that many people get stuck trying to get up, but not these trucks. Of course having the right tire and airing down always helps.

I’ve been reading about A-Trac, and it seems like an awesome system on rocky and snowy terrain. But how does it do in the sand? I can’t imagine how applying braking force while trying to make it up a soft sand incline would work? Would this not kill momentum? Sometimes in the deep stuff you just have to power through and keep your momentum, how would A-trac react? Further, A-trac is only active in 4lo. So if I mostly use 4hi, what would keep me from having only 1 front and 1 rear spinning in soft sand?

Anybody have any experience in these new 4runners in the soft stuff?? I saw Egstyle’s post a few days ago about his trip out to the dunes, those are AWESOME pictures, and that looks like a blast. But that sand is nothing like what we have down on the coast. Those dunes are hard packed and look pretty easy to get around on.

Sorry for the long post, any input is appreciated!

I take my '03 4WD 4Runner Limited out on the sand on Martha's Vineyard each summer. It does get soft in places, but there aren't any dunes or hills, so what I experience may not be similar to where you are going.

I air down to 15 psi and lock the center diff. I've never come remotely close to being stuck. My tires are nothing exotic -- Michelin Cross Terrains.

"what would keep me from having only 1 front and 1 rear spinning in soft sand?"

I'm not sure why a front and/or back would spin by themselves. Unless I am really wrong, on a SR5 or any other 4 runner once you place it into 4 hi, or 4 low, your going to get equal power to both front and rear axels, and thus, all 4 wheels will give you 4 wheel drive. I think! Now, with the limited, while you are driving normally, you are in "all wheel" drive. 40/60 power transfer between the front and rear axels. Maybe while in that mode, only two wheels, one in front, one in back, are actually your drive wheels, until you loose traction. I'm not sure about that since I do not own a limited. But once you lock in the center differentials in any model, you should get constant 4 wheel drive.

throw in aftermarket lockers front and back and hit the atrac off switch. shouldnt have a problem in anything if your locked front and rear.

good tires and bead locks will be a bonus as well. if you've got AT's and air down to 20-25psi with dual lockers i cant see you getting stuck too often

ARB makes a great locker kit for toyotas. give them a shout.

ARB 4x4 Accessories

The 4Runners have open differentials so only the wheel with the least traction spins the other does nothing. Happens in the front and rear when in 4wheel unless you have lockers.

atrac kinda tries to solve this by locking up the spinning wheel to send power to the one with most traction.


however, off roading i still think lockers are king.

The 5th gen SR5 and TE do not have a center diff. So you get equal torque to the front and rear driveshafts. However, that does not mean you get equal torque to each wheel -- you don't. The front and rear diffs are open, so that will give all the torque to the wheel with the least traction, unless something else intervenes, like ATRAC.

On the 5th gen, only the Limited has the center diff. You are correct that once the center diff is locked, it acts like a part-time 4WD system.

Locking front and rear diffs will give you the most traction, however they can also result in broken driveline parts.

ATRAC actually pulsates the brakes on the slipping/spinning wheel to either slow it down or stop it momentarily. This is done so that the opposing wheel (at the other end of the same axle) can get some torque/power going to it. The problem with ATRAC is that you have to slip first before it will intervene, so there must be slippage (aka potential lost of momentum) before it will act...and when it does intervene, it is a pulsating intervention, not a consistent locking of the axle. So, i agree with jca21 that in sand (and in most other off-roading environments), lockers are king. In fact, in the current Peterson's Off-road magazine (or FourWheeler i forgot which), there is a comparison of Jeep JK Rubicon vs. Toyota FJ. In the article, they said that the full set of lockers proved to be superior off-road over ATRAC.

When used properly, a locker is actually more environmentally friendly (less tire spinning needed) and, i would argue that lockers result in less stress on components than ATRAC. ATRAC sudden intervention on and off over and over again can create quite a bit of stress. Tierods have been broken due to this.

ATRAC is good when you have to do a lot of steering off-road. But, it can be a hindrance in situations where momentum is needed. And this is why i think that selectable ATRAC + rear locker combination to be a good compromise for most terrains...aka Trail Editions.

Thank you all for the education.....

i agree with Thai. lockers, when used properly will not damage the drive line.

I already contacted ARB back in January and the differentials are different then the 4th Gens.
Here is their response......

We don't have a firm date for the new locker but will be doing it. I expect we will see it some time late summer. We will add you to our notify list and let you know.

Jim Jackson
President
ARB-USA
720 SW 34TH STREET
RENTON, WA 98057-4814
Tel: 425-264-1391
Fax: 425-264-1392
Email: [email protected]
SKYPE: TRACTIONJACKSON
ARB 4x4 Accessories

only a matter of time my friend...

Why do you guys want a front locker on IFS? Personally, i would be very happy with the current Trail Edition setup. I would NOT want a front locker. Why? See: http://www.toyota-4runner.org/off-ro...formative.html

I just need a rear locker. I have a Limited without!
Thanks for the link though...looks like a good info. read!

Sorry, i am blind!! From the pictures, i thought that you had a TE. I did not even bother to read your signature carefully!