# A mystery. Cause of loss of control.



## CodeMatters (Aug 16, 2017)

Friend recently told me of a problem he had and it's cause. I'm going 
write the problem/symptoms here. Be interested to see if anyone 
correctly identifies the cause. I'll post the cause in a day or two if
no one has got it. 

Vehicle: Toyota Tacoma 4wd
Driving on very wet hwy, at hwy speed, with slush down center line. 
He wandered to left side of the lane putting left tires in the slush. 
He attempted to steer back to the right but found that he had almost 
no control and was unable to steer back to right. He let off accelerator
but the truck not only wouldn't move right but increasingly wandered
into the oncoming lane. Eventually, before the oncoming traffic was on 
him, he got down to a slow speed (sorry, not sure how slow) and 
traction regained and he was able to steer the left wheels out of
the slush and back into the right lane. He had plenty of tread and had 
never had anything like this happen before when the right side tires 
were on very wet, but not slushy pavement. Once he had all 4 wheels 
back on the wet pavement he had no more problems. 

What was the cause of this unusual loss of control?


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## de-nagorg (Feb 23, 2014)

Hydroplaning.

A common mistake here, too much speed road has too much moisture, then you float on the water, until you slow enough to get traction.

As I said it's a common cause of many collisions here. 

ED


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## Nealtw (Jun 22, 2017)

Hydro planing, he was up on top of the water.


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## CodeMatters (Aug 16, 2017)

More to it. keep trying.


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## lenaitch (Feb 10, 2014)

I agree hydroplaning sounds likely. He's essentially riding up on a cushion of water. He might have had good tread but some tread patterns are better at displacing water than others. A really big concern on motorcycle highway tires.


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## Mystriss (Dec 26, 2018)

My initial thought was break or ball joint seizure, but I'd say hydroplaning is likely if the problem didn't occur again - and, then, of course, how do you measure the intermittent occurrence of the two causes (ball joint and hydroplaning) when it can potentially be years between?

Hydroplaning is probably more common than black ice up here, we get ruts due to the frost heave and the water just pools in them, every lane change is a potential glider so folks don't like to change lanes next to each other. It's kind of an unofficial rule that you learn how to deal with it when you're taught to drive up here. I've heard that whenever it rains in California a bunch of people wreck from oil induced hydroplaning.


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## CodeMatters (Aug 16, 2017)

You're all on the right path.......but haven't got there..............


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## SPS-1 (Oct 21, 2008)

CodeMatters said:


> More to it. keep trying.



My guess would be an open differential in the drivetrain. That when he lost traction on one side, all the power went to the side without traction.


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## CodeMatters (Aug 16, 2017)

No problems with breaks, ball joints or differential.


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## CodeMatters (Aug 16, 2017)

Well I said I'd post the actual cause in a day or 2, but don't feel like waiting. 

The tires on the left side of his truck had been mounted properly. The tires 
on the right side however were mounted backwards. This resulted in the tread 
pattern channeling water to the center of the tire instead of away from the 
center as designed. Everything was fine as long as the left tires were on wet 
pavement but as soon as the left tires were in slush the hydroplaning of the 
right tires (due to reverse rotation) meant that NO tires had traction. 

So what's worse than a poor tread pattern? A good tread pattern in reverse 
rotation!


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## de-nagorg (Feb 23, 2014)

And here I am thinking that uni-directional tires were discontinued decades ago.

Just how old are his tires?

Yes that will do it, even worse if they all are backward, which can happen if they are swapped inside to outside on one side too.

ED


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## lenaitch (Feb 10, 2014)

de-nagorg said:


> And here I am thinking that uni-directional tires were discontinued decades ago.
> 
> Just how old are his tires?
> 
> ...



Still very, very common, especially with winter tires. My motorcycle tires are unidirectional and, as far as I can recall, the Coopers on the wife's Miata are as well (it's still in storage so I can't go look).


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## Nealtw (Jun 22, 2017)

I always like watching cars spinning down the road, foot on the breaks, no steering and when they finally give up and take their foot off the break, the car stops spinning and goes straight into a guard rail or ditch. 



Take you foot off the break and turn the wheel in the direction that you are sliding. And if you have not panicked and have time, keep you foot on the break until the car is close to the direction you want to go. 

Young people here are encouraged to learn how to drive on snow and ice in empty parking lots in their first year of driving.


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## Mystriss (Dec 26, 2018)

I gotta ask what kinda mechanic puts the tread on backwards? It's not like it's a hard pattern to figure out...

Semi-related; I always bork up the ABS on my vehicles because I'm not keen on it and do my own "feathering" I've only had ABS kick-in like four times in my entire life


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## huesmann (Aug 18, 2011)

So de-nagorg was right. Your friend was hydroplaning.


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## CodeMatters (Aug 16, 2017)

huesmann said:


> So de-nagorg was right. Your friend was hydroplaning.



Actually @lenaitch was closer in post #5 since he mentioned tread patterns.


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## MTN REMODEL LLC (Sep 11, 2010)

CODE... That was interesting.... I never realized unidirectional tread issues.

Thanks


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## Windows on Wash (Aug 30, 2011)

Technically...he was hydroplaning. The reason for it is what was in question.


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## CodeMatters (Aug 16, 2017)

Windows on Wash said:


> Technically...he was hydroplaning. The reason for it is what was in question.



Don't disagree, but I word it as: 
"Technically...he was hydroplaning. The reason for it is was key to 
understanding this particular scenario." 

And btw, other than hydroplaning, I didn't figure out the underlying cause either until my friend finished the story. 

Sometimes I'm happy just to understand the explanation and use that as 
a lesson in the future.

YMMV


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## Tom153 (Nov 10, 2016)

Thanks for the tip. I never heard of uni-directional tires. But I can see how they could be mounted incorrectly or rotated incorrectly. Will have to watch for such.


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