Close Call!

Man, I have to really agree with Mike...I know what he says is a fact...I live in a Valley in Nova Scotia where we get alot of snow and ice conditions to contend with and I know for sure when I'm in part time and hit the brakes on ice my open diff'd TJ will slide side ways every time...unlike my Grand Cherokee in Full time will follow a straight line everytime....

The other thing is, it has to be the tires...after reading this and running it over and over in my mind and being out on the North Mountain snow wheeling several times since I have a hard time grasping the loss of traction and not using gearing to come down the hills as I do all the time...it really makes me think that it was all a tire problem...I run a good tire!

Spdloader are you in an area that receives snow?? what type of Jeep do you drive??

Jeff

Your questions were answered in the former posts. You should read them in their entirety.

Spdloader

---if you get it stopped, aren't you in control?

---the vehicle will steer toward the path of least resistance. Rolling wheels offer less resistance than one skidding sideways.

---The original poster was already out of control, he was ALREADY sliding. I'm not debating how to slow down, but how to regain control once you have lost it in a slow speed incident. REMEMBER, the OP said he was driving slower than walking to start with.

---You mean, the wheels on the outside of the turn have to turn faster because they have farther to travel.

---I'm sure you've heard the saying "overdriving your brakes"? There is another regarding inclement weather, called "overdriving your traction". That is what causes those highway accident's in snow. But, this has nothing to do with the original post.

---When you are driving too fast for conditions, abruptly changing the wheel speed will break traction, whether you do it with the brakes, or with gearing.

---Obvious insult ignored.

I don't get it.

Spdloader

Bill, wake up and smell the coffee. Most passenger cars on the road today, American marks included, are front wheel drive. And I suppose you forget Saab's offerings, Cadillac Eldorado and seventies GMC motor homes, to name a few historical non-rice fueled front drive vehicles.

I do remember the first time I topped an icy hill in a front drive vehicle, planning to use engine braking down the other side. I found out fast, it doesn't work as well. I forget the year, but it was an air-cooled Honda

Earle

That's why I didn't get it. I said a rolling wheel offered less resistance than one skidding.

Spdloader

For once Bill is right about ABS. A wheel that is rolling, and whose contact patch is therefore stationary with respect to the road surface, grips the road better than one which is sliding. The reason why is covered in any elementary physics course.

He may be wrong about why people buy ABS though. I suspect that most of them don't have a clue, and like paying more for options with fancy-sounding names.

Earle

Heh, I still have a motorcycle endorsement on my Colorado license, which is good to 2012. The last time I was on a motorcycle was 1978. Maybe when I hit sixty, I'll get a Harley...

Earle

Every GM passenger car marque including Cadillac has a front wheel drive car.

That all depends on what you had to hit or where you end up to get stopped....

Not when in part time 4x4! Drop the shifter to 2 High and 'then' your theory works great. Yes, I 'do' drop to 2 wheel drive in some cases, especially when needing to turn at slow speeds in slush.

Go to a parking lot in the snow and start a turn. Then lock the rear wheels up with the emergency brake. The rear end will swing out and pass the front end faster than you can blink. Really. We used this method to make 'power turns' with front wheel drive vehicles when ice racing. We all practiced it so we could do controlled 360's or 180's or

Correct. He was attempting to drive 'too' slow down the grade. His tires just couldn't get traction going that slow. This made his tires scuff and break free just like jamming on the brakes. That is 'not' a controlled decent. Part of learning how to use 4x4 is getting the feel for the gears and engine compression so you can do a controlled decent. This decent will be at 5-10 mph. Try to go slower and the tires start to scuff and you lose control.

Which defines the front tires. They have to turn faster than the rear tires to complete the larger circle. This is the same reason you cannot use part time 4x4 on dry pavement. Either a front or rear tire 'Must' scuff the ground when you take a corner. If it doesn't, you 'will' break something like a u-joint or a t-case.

Letting off the gas in high gear so the engine starts the decelerating is not the same as jamming it into a lower gear. A Jeep will stop or slow down amazingly fast in part time 4x4 when you just let off the gas. Back to my parking lot to learn recommendation....

Not intended, it was a long day.

Mike

Front drive was invented here too.

IIRC, they were invented for aircraft, and first deployed in cars in the RWD Mercedes.

Dave Milne, Scotland '91 Grand Wagoneer, '99 TJ

True.

Yep, rear-wheel drive is much better for high-performance cars, when the drive wheels and the steering wheels are separated. But to say they "went back" implies that they don't make FWD cars anymore.

American engineered for Americans rear wheel drive? Wonder how many Mercedes and BMW's are front wheel drive...

: > From the discussion here, it sounds as if "part time" is better for going : > uphill, and "full time" might be better for downhill. There is lots of ice : > and snow outside, after a monster Colorado spring blizzard, but I don't have : > a "full time" four wheel drive vehicle to try this theory out. : >

: > Earle : >

snip

Tires are everything in snow and chains are everything on ice.