Getting into 4H?

I have a 2010 Tacoma. I have never driven a 4wd where you hit a switch to get into 4 WD High. . The book says that you must be driving to go into 4WD High. (Yet to get into 4WD Low it says you must be stopped in neutral.)
My question: If I come out of my house and discover an 8 inch overnight snowfall do I have to attempt to drive the truck before putting it into 4WD High, or can I start the truck and just push the switch?

 

I just put the my truck in Neutral and then flip the switch on for 4H. You'll be fine not driving and then switching it on.

 

I turn mine on stopped, sometimes it blinks sometimes it goes right in.

 

Mine also blinks sometimes and goes right in sometimes; however, more often it blinks rather than going right in if I am stopped. I wish it was like the old fashioned manual locking hub type with the floor shifter that I knew went in as soon as I shifted the 4x4 shifter.

P.S. On the other hand, the more I think about it, I don't think mine goes into 4wd high until I put it in gear and let out the clutch, if I am at a complete stop. If I do it this way, I am very careful to make sure not to spin my tires when I take off. I don't do it that way very often. I am usually in gear and moving when I put it in 4 high.

 

Its not a waste of time, what these other guys are saying is that you don't have to be moving to push the button, it all depends on whether or not the gears are lined up. moving makes the gears line up faster. and the manual stating that you must be moving is for that reason. all you need is to take your foot off the brake and move about a foot. In other words, you can engage 4h whether you are moving or not, just sometimes you may need to roll forward a bit to get it to engage. but the 4L you must stop.

 

If you took apart the system the way it is designed teeth on a gear have to line up, when stopped, if you engage 4Hi the light blinks telling you it has sent the shift motor the signal, is trying to engage the gear, but the gear has not be fully engaged - the light goes steady when the gear is engaged. not sure if this is based on actual gear position, or feedback from the motor shaft position (shaft encoder, or hall effect sensor for the gear). Either way the manual says it is safe to engage 4Hi safely while moving and at a fairly high rate of speed. It hurts nothing to attempt to engage it while stopped if the situation you are in dictates that action. 4Lo is different, the way the gearing works if you were able to actually engage 4Lo while in motion, that would be bad juju and you would quickly find the weak link in your drive train. However sometimes when you click into 4 lo while stopped the light may blink, sometimes it may be necessary to "rock" the truck a smidgen forward or backward to let the teeth engage each other.

 

So, whats best in this scenario... Say you get completely stuck in snow while in 2WD and can't move due to wheel spin...no traction. If your try to get into 4WD while stopped and get nothing but a blinking light...what do you do? I suppose hitting the VSC button to turn off the traction control to enable auto LSD is an option, but if that doesn't work, is there any other alternatives?

 

If your wheels are spinning, then the drive shaft is turning, if the drive shaft is turning, so are the intermediate shafts and gears inside the transfer case, if they are turning, and the shift motor is putting pressure on the gear to slip it in place, and everything in the universe aligns, then the gear will find its happy place and you will find your self in 4wd.

now if for some reason you are stuck, in 2wd, and you can not get either tire (left rear,right rear) to spin, you would probably stall your engine if you wern't quick with the clutch. At this point, depending on how much of an emergency you are in, you could either get someone to pull you out, use the winch (if installed), or last ditch, disconnect the rear drive shaft, reattempt to engage 4wd and pull your self out that way (here is were a front locker might become useful)

 

4 high I dont stop. If you have a manual transmission and the light blinks, sometimes its because the clutch is not pressed in all the way.

 

True, I noticed when I switch from 2WD to 4H while moving it locks in really quick. Switching while stopped takes a while for it to lock into 4H.

 

it will go into 4hi from a stop fine. if the light is blinking just put it in gear and letting off the brake is usually more than enough. If it still is blinking, put it in reverse and let off the brake. It just needs to get the gears aligned to engage. Put your truck into 4hi / 4low once a month to keep everything working, plus then you will know exactly how it works

 

If I was worried about waking up in a foot of snow in the driveway, I would just put it in 4HI just before I parked for the night. That way your covered and if it didnt snow just take it out of 4x4.