Sluggish/lag when transitioning to 4WD

[Merle]

Is it just me, and/or something I need to be worried about?

With a good set of tires (GYSA), the 4Runner runs mostly in 2WD, even with some crazy weather/terrain.

However, when it does transition to 4WD (or I think that's what happens) it feels like there's a loss of power followed by a delay in getting going. On rocky (uphill) trails I have to literally floor the pedal to get going and on snowy (uphill) roads it seems to take longer to get going before I actually "get going".

I'm not seeing anything happen with the RPMs, *maybe* the traction control (VSC) kicks on but not enough to kill all the power. It lasts for 1-5 seconds and then things are totally fine (even with the VSC light on and making noise).

 

[Uneek]

What year is your 4Runner? It is a V8?

Mine shifts easily from 2H into 4H, even when stopped. Occasionally, it might require a slight roll or wiggle of the steering wheel to get the gears in the transfer case to line up. I almost never need to give it more gas or rev it.

For ATRAC when there is some slippage of the tires, revving it to about 2000 RPM seems the most effective to get the 4Runner to start moving and let ATRAC modulate the brakes on the slipping wheels.

 

[Merle]

Yeah, it's a 2008 V8 4WD limited. I don't get the option of manually engaging the 4WD as it's automatic. I used to think it was linked to the VSC but can't be 100% sure and think there's a delay in a) figuring out that the VSC isn't doing its job and b) the system trying to engage the 4WD and then c) it actually engaging. In a..c I'm thinking thats where the lag is coming from.

 

[Merle]

Just an update for today...

Drove over to Heavenly and found a "bad" parking spot (hate walking in ski boots) but close enough to make it worthwhile. Basically the front end dropped 6" (or more) into a culvert though I didn't bottom out or high center myself on the frame.

Stuck it into reverse and it backed up roughly 2/3'rds of the way and I took my foot off the gas (4Runner didn't move). Thinking I needed a little more of a safety margin (to get out of the ditch now versus at the end of the day) I hit the gas again.

Nothing. No RPM change, nothing.

It was snowy area of the parking lot, moderate ditch w/ incline. Not wanting to gun it (car on my right and large snow bank on my left) I took my foot off the gas, waited a second and then lightly applied pressure.

It backed up w/o a problem.