4wd function

Sometimes things aren't lined up perfectly when you hit the switch. Pressing the accelerator, in some circumstances, will take the pressure off the ADD components and allow it to lock into 4WD. Same reason that when you're stopped, if you go from 2Hi to 4Hi, it doesn't always engage.

 

At the Dealer I was told you are able to go from H2 to H4 on the fly, no need to let off the gas (under 60mph tho). They actually recommended giving it gas while changing over

 

I find that if I am moving but not giving it gas, that works the best
(2->4H).
If I am on the accelerator when changing into 4H, I sometimes get a
clunk, I figure that is not helping anything.

 

x2

 

I had to shift into 4 hi last night on an icy hill, and forgot to let off the accelerator...got a pretty good clunk out of that. I agree with no accelerator, it has to be better on the system...

 

Yeah, I had lost traction on an icy patch, and my brain froze just like the street, and I forgot to ease up before switching on 4wd...it did engage, with the aforementioned clunk, and got me up the hill...

 

I totally agree with everything about not shifting it while accelerating and was very hesitant, and to prove me wrong the guy at the dealership switched it over while I was accelerating onto the freeway going about 45mph. I didn't even feel it change over. Either way, I'm not agreeing with him or disagreeing with him, but in the future I will most likely take my foot off the pedal just to be safe.

What's funny was that this guy at the dealer was their truck master, and that is why he went with me on the test drive. His title was "Toyota Truck Champion". He seemed to really know his stuff, and was a great guy!