What happens when 4runner is in 2 wheel drive?

I am coming from a 1500 Silverado and it has been decades since I owned a 4runner (2003), with the new 2024 TRD off road premium that I just purchased, what happens when you are in 2 wheel drive and hit gas in a slippery situation? Is the power going to just one wheel or both? I am not talking about the locker of course. Just stopped at light and it's slippery. Thanks!

 

It's an open diff, one wheel will start to spin then traction control will kick in.

 

As far as I know 4Runner have open differentials and TRAC with VSC for electronic traction and stability control. So power will go to the wheel wihch doesn't have traction and then TRAC will try to apply brakes to that wheel. From experience you should expect wheel spinning, beeping and flashing TRAC light and then truck will move if it's not very slippery. If you are doing shrp turn on slippery surfaces and start fishtailing - VSC will try to apply brakes to align your trajectory with steering wheel angle, but it's not overly aggressive. I experiences that just once on left turn and VSC helped, but I had time to be scared : )

 

I have no idea but...initially power is going to both wheels equally (right?), and then because one has no traction, that amount of power makes the wheel spin, THEN because the system senses this it applies brakes to that wheel (but is still giving 50-50 power?), so the end result is reduced spinning/slipping.

Correct?

 

If I am not mistaken the traction control system also reduces power.

 

This exactly... you hear some clicking and the stability control light flashes yellow on the dash then the system kicks in and starts to brake the spinning wheel... depending on how much it spins it may also chop the throttle.

This very rarely happens to me on rainy days if Im too aggressive on the gas turning into an intersection from a stop etc. Most times it happens is in winter on slush and ice and when it becomes consistent that's my cue to go into 4H. and slow down.

 

OK, so in addition to applying brakes to the slipping wheel, it moves from 50-50 to some other power ratio to give more power to the grippy wheel. Good.

 

Open diff so power will follow the least path of resistance. The electronics will come into reduce wheelspin and transfer power to the other wheel which hopefully has traction.

 

TRAC isn’t to be confused with A-TRAC which is an option to put on when in 4L and pretty extreme scenarios. Regular TRAC is on all the time, though.

 

Here you go, it's a long read, but good information. Ignore the T-word, it's the same system:
https://www.tacomaworld.com/threads/3rd-gen-traction-control-modes-explained.530695/

The VSC button is the car with squiggly lines below it. (Near the locker button on the Off-Road models, not sure on SR5).

The manual has some of this info, but not everything that happens behind the scenes.

 

Thank you everyone! Great info!

 

In 2WD on my 2019 ORP the main drive is on the rear wheel passenger side.
I tested it with the bad Dunlop Grandtrek AT 20's on a wet road when switched off traction control.
Accelerate in left corners and the rear breaks out dangerously, in sharp right corners it almost come to a stop and the rear wheel passenger side spins endless.
As soon as VSC is active you can hear the brakes and it tries to suppress slippage.

Greetings from Switzerland

 

Just don't rely on it too much. Last winter I was driving on a country road with patches of snow and didn't turn 4Hi becuase those patches were small and it was mostly slighly wet asphalt. I was going through show patches just fine, but on one of them truck start fishtailing so badly that I had hard time to maintain control of the truck, I was all over the road and ended up on a shoulder. I guess TRAC and VSC helped me but if there were any cars on incoming lane or too close behind me or trees by the road - I would end up in bad accident. Since then I turn 4hi every time I see slippery surface starting from heavy rain. Transfer case hold this just fine for past 11 years. TRAC and VSC help but not a lot.

 

As long as there aren't large patches of dry pavement you can use 4H.

 

In my 11 years experience driving 2010 SR5 I used 4hi in winter on large lengths of dry pavement if there a chance that snow patches blown from the fields are ahead. Like 20 - 40 miles with few 60 feet long snow patches on that distance. I think it's OK to drive in 4hi on country roads at about 50mph where there are no excessively sharp turns. At least my T4R transfer case didn't have any issues. To me it's better to replace transfer case than total whole truck in an accident or possible injure others. But as I said my T4R was just fine unless got t-boned in the city intersection in nice sunny weather. By the way one time TRAC and VSC was straightened my up and saved from embarrassment in the rainy day when I was doing left turn in the city to fast. So it works but not always and everywhere.

 

It's because that wheel has the least weight (you+ gas tank on driver's side). Mechanically it shouldn't get any more torque than the other side.

 

Not sure about today, but my 2001 got away from me years ago when I was in 2WD on a perfectly straight road under very light acceleration and hit ice. Experienced slip, then traction control kicked in abruptly and threw the rear out to the left, and off the road I went. Driver side mirror hit a speed limit sign and came off. Otherwise no damage. Lesson learned.

 

My 2003 did the same thing. Almost took out my neighbors mailbox. Hence the reason I am asking.

 

The default settings (throttle cutting and braking) should be best for roads, including wet and icy. Cutting the throttle helps the spinning tire grab again.

Selecting the Auto LSD / Trac off option (pushing the VSC button once) makes you much more likely to kick the back end out on slippery pavement, since you can more easily break traction on both sides.

Letting off the gas instead of trying to power through usually helps too. I did a very rapid 180 in my Rodeo once on an icy road, thinking I could steer through the drift like I was on dirt.

 

Thanks for the hint. Yes, it could also be due to the weight distribution, i just noticed that the behavior in right and left corners is quite different. Left turns are much more dangerous/critical than right.