Rolling Backwards on Steep Incline in 4HI and Harsh Shifting in 4LO

I got to put my truck through its paces a few weeks back in Colorado. There were a few times where I was climbing a steep hill in 4HI and had to stop to check out an obstacle ahead. After getting back in my truck, I would press the brake, release the parking brake and shift into drive. Before I could get my foot on the gas pedal, my truck would start to roll backwards and a clicking noise was heard. I think the VSC light started flashing as well, but my memory is a bit foggy on that. From what I understand, this is normal, its part of the hill assist feature. However, when hitting the gas, it seemed like I had no power, and I would continue to roll backwards. This was especially pronounced when the incline was over 15-20 degrees.

My memory is foggy now on exactly what I did at different times to deal with this. I know for certain that shifting into 4LO would fix it. When in 4LO, the vehicle would just stay stationary until I hit the gas, I never got the clicking noise or any rearward travel. One other time, I think I tapped the VSC button to turn it off. I thought that maybe VSC was throttling the engine, and not allowing sufficient power to be applied to the wheels. I can't remember though if that worked. If I had to guess based on fragments of memory, I don't think it did.

So the question is, did I just not give the hill assist enough time to work? If I had continued to apply gas in 4HI while the truck was rolling backwards, would I have eventually stopped the rearward movement? For really steep inclines, do you just have to switch into 4LO?

I should note that the sound the vehicle makes is very close to the sound my previous Ranger used to make when it had trouble engaging 4WD. That used to always skeeze me out, as I figured I was stripping the mating interfaces in the locking hub. If the clicking is harmless, I might put a bit more faith in it and give it more gas to see if that works next time.

The other item I have noticed, is that in 4LO, the shifting and/or throttle control seems to be really harsh. Basically it's like the normal transmission behavior everyone laments, where you step on the gas, nothing really happens, and then boom you are moving. Only it seems magnified by a order of magnitude, to the point where you feel like this has to be hard on driveline components. I am guessing this is normal for this vehicle, but just wanted verify.

 

Cutting power sounds like a VSC thing. If I had to guess it was starting on an incline was tricking the computer into activating. Perhaps you need to start level before climbing for the systems to understand? In low range VSC is not active, just the A-TRAC.

 

Interesting, I just posted something similar to this before seeing this thread. My truck doesn’t even have to be in what I consider a hill it can be the slightest grade like pulling out of a gas station onto the road

 

We had a 2005 4Runner for a short time and one of things I hated was VSC kicking in on wet pavement. It was borderline dangerous trying to get through stop lights in the snow. It would cut power and you would creep through just waiting to be T-boned. At least it had a switch to turn it off, which seems logical, you know, disabling stability control in bad weather.