Couldn't stop going down hill in snow.

[buckland]

Take the foot off the brake and drop into low (or first gear).

 

[BillTheHiker]

Had a similar thing happen last week. Going downhill about 25 mph on a switchback with wet asphalt and a few spots of slush, I came upon a snowbank cutting machine crawling at maybe 1-2 mph. I hit the brake pedal hard and could only slow down but not stop, so I switched from 4WD to 2WD and stopped very quickly.

So I did a little online research, and based on a couple technical articles from sae.org, learned that ABS does not function properly when in 4WD. They don't say it, but imply that it could make braking worse. So next time I go downhill I will be in 2WD.


https://saemobilus.sae.org/content/880322/

https://www.sae.org/publications/technical-papers/content/890832/

Above are abstracts; full content is $33 USD

Following is not from a scientific source like the above, but seems consistent with SAE papers and has some additional information:

http://www.4x4abc.com/4WD101/ABS_parttime.html

 

[Casa Escarlata Robles Too]

Not sure that the owners manual gives any info on that.
My 4X4 Tundra is a used one to me and there wasn't any manual.
That's good to know though.
Frank

 

[PaulT]

My 2010 Tundra disconnects the traction control (based on the ABS) when in 4LO but it is active in 4HI. Haven't had to test just the ABS under slick conditions to see if it works ir 4WD, but I suspect that it does work.
There is an idiot light that illuminates when traction control is disabled.

Paul

 

[Casa Escarlata Robles Too]

My Tundra is a 2002 and it doesn't have traction control.
Doesn't matter much,I very rarely drive in the snow.
Actually the first and last time was Nov 2013 coming home from Zion.

As it turned out we hit snow on Carson Pass.

Any info is still useful.
Frank

 

[buckland]

No matter what..... stop (if possible() be sure to be in 4WD... put into low (automatic or 1st standard)... descend (you will notice you are accelerating .... is ok) the gear if automatic will kick in....resist the urge to brake...NO BRAKING... the truck will kick in and you will slow in a controlled way. If you touch the brake.... no... skid starts (on ice)... I have a steep 850 foot driveway/dirt road with a 20 ft drop off into a stream on either side (old stone "bridge").... need to be going straight . Breathe. (or whiskey).... over compensating is the devil.

 

[wicked1]

thanks for the additional replies. What Buckland says is what a couple guys told me in person as well. I need a practice hill w/out drop-off of death on one side, to test the various suggestions .
I really think if I were in 4 lo, and just rolling, I'd have been fine..
But there does have to be a breaking point.. Where even then, the snow/ice gives up the traction. I'll buy a set of chains or tire socks, too.

 

[JimBow]

I had KO2's on my Tacoma. I think they're terrible on ice and snow. They may be OK when they're new, but they harden with age. For winter, I now have General Grabber Arctic studded tires. Much better. I live in the mountains where it snows quite a bit, so it's worth having studded snow tires.