New owner 4Runner TRD ORP - questions about engaging 4WD

Hello - I have some very specific questions that aren't quite answered in the manual and difficult to search online:

1. Can I go from H2 > H4 while slipping?
   
   If I'm in H2, on a low-traction surface, the car is stuck and one and/or both rear wheels are spinning - can I engage H4 and very gently apply throttle until 4WD engages? Or is this bad practice that'll shock the drivetrain?
   
   The manual states:
   
   
   
   This is confusing because it implies you can do what I'm asking above as long as you switch into H4 off-throttle. These days, it's also hard to tell whether their rationale is mechanical or legal - like omg the car might suddenly jerk and you will die.
   
   >>> What confuses this situation further is this section re the diff lock in the manual:
   
   
   
   Are they assuming you're already in H4 here? It doesn't state that, anywhere.
   
   
   
2. Is full H4 engagement (solid light on the dash) required prior to shifting into L4? Or can I go straight from H2 to L4 from a dead stop?

 

Answer 1: If you're slipping you should not try to go from H2 to H4. But if the wheels are NOT slipping, you can shift from H2 to H4 as long as you are driving 60MPH or less. It might be 65MPH. Someone correct me if I'm wrong.

Answer 2: If you want to go from H2 to L4, then you must come to a complete stop on a level surface (preferably), drop it into neutral first. Then shift into L4. You'll hear a click and see lights come on the dash board. Waa-Laa, you're in 4Low.

 

Do not shift while slipping. You should be moving forward in a straight line under the max shift speed of 50ish. Let off of the throttle and select 4wd. You need to be in high before going into low.

 

You can engage 4hi while moving up to around 60mph. Remain off throttle while shifting the transfercase. The transfercase is immediately engaged due to the manual lever. The front differential is electronically actuated and is only engage when the indicator stops flashing.

Engage 4lo only when stopped and the transmission is in natural. You can shift smoothly from 2hi to 4lo without pausing in 4lo or neutral.

The rear differential lock will only operate when the vehicle knows that it is in 4lo. It will not engage in 2hi or 4hi.

There is a 4wd operation card on the driver side sun visor

 

Thanks - did some experimentation today. I think in summary:

1. Avoid going from H2 > H4 while slipping/with wheelspin
2. However, engaging from H2 > L4 from a standstill seems instantaneous - i.e. the 4WD indicator is solid green and all the 4LO + other indicators turn on right away (no driving seems necessary). So I guess if you get stuck in H2, going into L4 from a standstill seems like a reasonable next step. Maybe this is why the manual doesn't state anything about going into H4 as an intermediary step, above?

Happy to hear other experiences. This is a 2023 FWIW.

 

I think it’s slightly different depending on the trim but for the one with the manual transfer case I think it’s no more than 50 mph

 

I would suggest that if there's any chance you might get "stuck", you should be in 4H rather than going from 2H to 4L. If 4H isn't enough, then select 4L.

 

There is some good info and some bad info in these responses so far.
1. Going from 2H to 4H: do not do this while the rear wheels are slipping, very good chance of breaking something. It is easier to get into 4H while the car is moving, though, and the max speed is both in your manual and on your sun visor. Best thing to do, since you are unsure, is to shift into 4H as soon as you get onto the dirt road (while moving). The more you do this, you'll get a feel for how it works, and how to make it happen quicker.

2. You can't go straight from 2H to 4L, even if you think you are. The stick has to move through the 4H position first, no matter how you do it. While you can technically keep shifting the transfer case over to low range, you should really wait until the front differential is finished connecting before moving on.

If you're in a hurry, and trying to apply gas during these steps when you're stuck, you have a good chance of breaking something related to the front diff, and the added torque from low range is only going to make it worse.

Just saw the diff lock section: if you need the diff lock, then you should have already been in 4wd. And on the diff lock advice of giving slight throttle to get the locker to engage when stuck: this is a different setup than the front differential disconnect system (I assume this is where you got the idea for your first question).

In the rear diff, the starting condition is that all 3 shafts are connected, and you just need left and right to line up to lock them together (the speed difference is minimal). The locker is used when one tire has minimal traction in the back, so the amount of throttle needed should be minimal.

In the front diff, the starting condition is 1 input and 1 output are connected, and 1 output is disconnected. You want all of these shafts going the same speed (or stopped) to ease the connection of the last output shaft. Sometimes they need help lining up, which is why it's easier to shift while moving (I like to turn gently, too, personally).

However, if you're giving it enough gas to spin the back tires to try and get the front driveshaft to move, you're more likely to break something if it does connect.

Rocking back and forth a little would be much better, in my opinion, to help get into 4H if you find yourself stuck while in 2H. Best bet is don't get so stuck you can't move at all in 2H (this takes some experience and some actually getting stuck to learn, though).

 

Thanks for the close read.

Nope - I understand the difference. Not new to cars, but am new to this off-road stuff. If you know of a good diagram of this system, please share - everything I'm finding is from the 1930s, when the first 4Runner was built.

My last remaining point of confusion is this:

I completely understand what you're saying here & am familiar with the layout. What I'm saying is: Going from 2H to 4L, when stopped, illuminates this indicator immediately:



Solid green - right away. Tried this four or five times from a standstill - same behavior each time. Unlike going from 2H > 4H, which takes a short bit of driving & blinks until the ADD engages. Are you telling me that if I go from 2H > 4L, despite the indicator immediately going to solid green, the system is not yet fully engaged? i.e. - the indicator is misleading? I also came across a YT video where some dude also suggested it was immediate because of the different ratios but... everything with a grain of salt.

 

Going from 2H to 4L can happen but it’s rare. Better to just go to to 4H first. Also green just means 4wd is locked in but you have a separate low light.

 

Maybe the front locks in easier when you're in neutral? (Because you must be in neutral to go to low range). I don't know why else it would work instantly, but only when going to low. Maybe the transfer case going through neutral helps as well.

Could try stopping and shifting to neutral when going from 2H to 4H to see if that's it, but personally I'd just go to 4H as soon as conditions allow.

The system needs exercise (lubrication), so more use is better, and running 4wd generally results in less wear on the road/ trail.

 

https://www.youtube.com/watch?v=47m7QAPrpsI&t=13s

https://youtu.be/1a9JQC6fgXw?si=BrrGum31SSmd021u&t=2883

 

Also you should have 4wd instructions on your visor.