Close Call!

Mar 12, 2006 89 Replies

Not in a 4x4 with a locked center diff or 'part time' drive. See explanation below.

I think folks should go out to a parking lot to learn and see the differences, but as a general statement, using the gears to slow down is better than brakes in a 4x4 with a locked center differential or in 'part time' 4x4.

Neutral just don't work because when in a slide with the wheels turned, the front wheels still have to travel 'farther' in the circle to come back straight. This means one back tire or one front tire has to scuff the ground or start to slide sending you into a worse slide or really fast 360's. You have to have power to overcome this wheel scuff or it's like locking the brake on one front ot rear or both tires.

No it doesn't. See above. The center differential isn't there in part time 4x4 so the front and rear axles are locked together. In your cruiser, you can lock the front wheels and have the rear wheels push you still. In part time 4x4. the back wheels stop turning at the same time as the fronts.

The transfer case locks the front differential to the rear. On snow, lock the front wheels and both back ones normally lock because all four were seeing even torque.

They then hit the brakes to slow down maybe dumping the clutch, maybe not as in an auto and as soon as the front tires skidded, the rears skidded and off to the low side they went faster than they can blink. Just like pulling on the emergency brake half way around a corner. Try it, it's fun...

If they had of used the engine to slow down, they would have been able to make the corner most likely. Really, try it...

Give me a break, I used to race on ice tracks.... We lived where you never saw bare roads from November until spring thaw, they were all ice roads. My wife has to drive on ice roads to work most winter days still and she never uses the brakes while calmly driving by all the fender benders and snowbankers.

Jeep 4x4 works 'really' well when you learn it.

Mike

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

4X4PLAY,

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.

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

600.

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

90's....

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

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06
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(More Off Road album links at bottom of the view page)

Front drive was invented here too.

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Earle

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

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

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...

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