Stupid snow/city.

[dac]

Can someone explain to me how the brake system is connected to the transfer case?

Sorry if I'm understanding your question wrong.

If you have it in 4x4 the front brakes can't lock up without locking the rears up, because it's in 4wd, front connected to the rear which Pat so elabourately explained.  So, you are more or less using the front brakes to help the rear slow down, before they (the front tires) lock up and you effectively reduce the braking force of the front, because they start sliding.

So no, the brake system isn't directly connected to the transfer case but rather works through the transfer case.

Sorry...that's the silliest thing I have ever heard.  If anything, the force from the engine that is transferred to the front driveshaft keeps you from braking better....the brakes now have to deal wit rolling resistance, AND the force from the engine.

Talking stick, if you don't have your foot on the clutch, so in gear, and you have it in 2wd, the force from the engine goes to the rear diff, so the force of the engine is there if you're in 2hi or 4hi, makes no difference.  Auto, it's still there but you have some play.

Well if it were mathematics instead of engineering, perhaps I could try.

Maybe there are some engineers on here, but correct me if I'm wrong but, don't math and engineering kinda go hand in hand?

I started out pointing out the engineering reasons behind a limitation of the part-time 4 wheel drive and look at the battle that ensues!  I didn't realize giving someone the actual underlying engineering so that they can make an informed choice was such a crime. Perhaps we should keep them in the dark and uninformed.

I think the battle is from you trying to use the "I have an engineering background card and have an answer for everything" that most people have the problem with.  I've had to fix a lot of problems because some engineer doesn't really understand how stuff works; sits behind a desk, knows the theory but has never seen the real world.

I think what Tom and Todd are trying to say is that they know how their 4x4 systems work, it can make your commute more safe if you know how to use it and drive defensively.  It also may help you stop more controlled.  Me personally, use 4x4 if it's slippery.  I know I can get placed eventually using 2wd but it can be a pain spinning out, wide tires (I'm sure most people also have MT's maybe siped; less than optimal on ice) on a short wheel base vehicle.......  It's not worth the risk of the back end kicking out going down a main stretch of road if you know it's slippery when you have the option of using 4x4.  Especially considering the manual states you can shift between 2H and 4H up to 88kph.  Thus implying it's ok for slick roads in town.

[BBD]

it all boils down to common sense. if you dont use it, 2 or 4wd isnt going to help at all. 

[frenchy]

The biggest safety concern to me on slippery roads is stopping, I don't think 4wd really helps that.

What does, is weight and good tires.

I've got an extra 2500Lbs on the truck right now, only had to use 4wd on that one Icy Friday, rarely spin a tire and ABS has only come on a few times.




Oh, and do I need to put a disclaimer in here that I do not hold an engineering degree and that these are my thoughts, not yours 

[Hi Lo Silver]

I'd be willing to bet that having the front end engaged would increase stopping distance wet, icy or dry. Engaged, the minute you take your foot of the throttle your rig is working against more running gear. Slightly more friction with all the extra parts turning. Same idea as coasting down hill in 2wd or coasting down hill in 2wd with it in gear. Just seeems logical to me.

[TJ54]

my 2 cents,

I put studded hankook winter tires on my wifes caravan, they are friggin' awesome, can go any where, and the van stops almost like on dry pavement,

I put hankook's without studs on my golf, they perform really well, night and day difference between winters and all seasons.

I remember driving my old two wheel drive (one wheel drive ? ) pickup on icy roads. It sucked big time. If I had  4wd i would have used it as often as possible.

I lost track trying to understand the technical fulltime part time locker discussion. Maybe using 4wd on a vehicle could damage it ( not sure how ) but a broken vehicle can be fixed alot easier than broken people.

 well actually not really, it's cheaper to fix broken bones rather than dented fenders   but you probably get my point.

[TJ54]

I'd be willing to bet that having the front end engaged would increase stopping distance wet, icy or dry. Engaged, the minute you take your foot of the throttle your rig is working against more running gear. Slightly more friction with all the extra parts turning. Same idea as coasting down hill in 2wd or coasting down hill in 2wd with it in gear. Just seeems logical to me.

if your foot is hard on the brakes, and wheels are locked up and sliding, it doesn't matter if you are in two wheel or 4 wheel drive.

without the wheels locked up and skidding, wheels still turning, you maybe right. But i'd take that bet, because i think it would be a very close call.  what you want to bet ? a tim hortons gift card    nothing to big 'cause I might lose 

[TJ54]

they are friggin' awesome, can go any where,

I wanted to prove this by taking it to the falls, but she wouldn't let me

[Hi Lo Silver]

if your foot is hard on the brakes, and wheels are locked up and sliding, it doesn't matter if you are in two wheel or 4 wheel drive.

without the wheels locked up and skidding, wheels still turning, you maybe right. But i'd take that bet, because i think it would be a very close call.  what you want to bet ? a tim hortons gift card    nothing to big 'cause I might lose 

My question would be, why are your brakes locked up and skidding to begin with? There's never any braking power to a rig locked up. That's why old school rigs you pump the brakes and new school have anti lock. That way the rig slows you down with gears and friction.

Tim Horton's card...ouch....I'm just a carpenter not an injunear.

[Joel]

it all boils down to common sense. if you dont use it, 2 or 4wd isnt going to help at all. 

Couldn't agree more.  Really frustrating when people don't use there brain...ooops sorry forgot that's optional now a day's.

Most common things I see is a fwd car approaching an icy intersection with a slight incline, they chose to stay on the shiny black ice.  Instead of picking their line and putting a tire on the pack snow, where the gravel's been cumulated.  When the green light turns, they floor it and wonder why they're not going anywhere.  Or leaving enough space between the car in front of them, and slowly inch forward, so when the light turns green they're not at a complete stand still.   Small things that can help traffic flow.

I don't drive around in 4WD during the winter unless I can feel the road is icy or there's enough snow that I can feel the Cherokee sliding when changing lanes.  This year I bought a set of Studded Winter tires for the jeep, and even with the amount of snow and icy roads the past week, haven't really felt the need too shifted to 4wd.  Except for the odd time I want to play and mess with people's mind at the lights.  Shift to 4WD, giver gas and she takes off instantly.   And yes, she comes to halt in hurry when you need too.

The tires have pretty much paid for themselves, emergency braking to avoid an accident on crowchild, and the fact that I don't drive around in 4WD saves me tons of gas.

[crane man]

Haha, i have to get in on this debate ! full time 4x4 is just what is says, its full time! with the np203 transfer case you have a 4 hi, 4 low ,4 hi lock and 4 low lock, these transfer case's had a differential to "split" power between the front axle and the rear axle, it works just the same as an open diff in your front or rear axle, unless the both front wheels are locked up by an obstacle or whatever, the front drive shaft always turns, but can turn at different speeds than the rear axle!
part time 4x4 with open diffs, will cause the truck to hop and chirp tires in high traction situations when you are turning, because the front and rear axle have different distances to travel when turning.  part time systems are more efficient than full time as there are less parts turning when in 2wd.  auto locking hubs allow you the efficiency of a part time transfer case with benefits of full time 4x4, you can easily shift 2wd before turning on high traction surfaces to ease some of the stress on drive line components.  i personally drive my tuck in 4x4 when there is snow on the road and almost always drive 2wd at speeds over 80 kph. i definitely agree there is added stress to the drive line in 4wd . in my opinion the benefits of being in 4x4 are far greater than the disadvantages of not being in 4x4 on low traction roads. in 4x4 i notice my steering is stiffer my turning radius is larger and my truck is a bit noisier, but i can corner faster, stop quicker, accelerate quicker, and my favorite to be able to drive though snow banks, lanes that are undrivable to other vehicles and take short cuts . the one thing this gives me is the ability to drive out of any situation, where as in 2wd i don't have as much control.
In short full time 4wd is not a true 4x4  it is the same idea as in awd car and can be driven on any surface with out any concern. Part time in theory should only be used when needed, and can cause considerable wear on components when used on dry high traction surface.

[JackstandJohnny]

Well if it were mathematics instead of engineering, perhaps I could try.
Stunting eh?  I don't like the people not able to go, if the intersection is that slippery as many are, then I use 4x4 to get going.  Many of the 4x4s are probably engaged, but if they have a part-time system, then they can still spin one wheel without traction control or lockers, two if they put it into full time 4Wd and don't have traction control or lockers. Many of them also have the crappy all-seasons that come on the vehicle from the factory like Michies Liberty had. They were *terrible* even IN 4x4.
Then with all the increased braking, traction and control, I suggest that you drive in 4x4 all year around since there is negligible slippage.  Shouldn't be a problem whatsoever

i always thought engineering was the application of mathematics and physics. is it not?  i'm not much for equations and the like, so i go with what i know:
4x4 engaged slows the rig down while NOT on the brakes.  this is good; brakes on ice tend to make for locked up rigs and sliding........... heavy vehicle + speed - traction = slip'n'slide.  so i try to stay away from brakes.  thats physics.  i also know good tires can slow that equation down cause it increases friction!

4x4 helps me go quicker off the line.  i like that.  I also know that winter months have a lot of snow/ice/slicker conditions, so i  keep it in 4x4; i've heard that the torque split to multiple wheels is good because instead of one tire pulling with 100% engine force, you have two tires, with twice the surface area, and half the torque power.  this is mathematics and physics.  i'd rather not talk about the physics of lockers and why it doesn't help this situation though.  (not an engineer so i don't know)
thats my mathematics. i don't bother with the minimal difference between what looks to be 'dry' pavement in the winter and snow covered pavement.  guess i'm just lazy so i leave it engaged in 4x4.  in regards to runnin it in the summer, i wouldn't do that either. thats silly.  we know 4x4 is harder on things especially when you have good traction. i don't think theres a lot of city roads with 'really good' traction right now; so i'm cool with 4x4.  benefits outweigh the drawbacks in my book. 

anyways, regardless, drive safe out there. its been stated before, this is all means nothing if you drive like an idiot........... 2wd, 4wd, brakes, whateva. don't matter if you don't have common sense.

[Mudhawg]

in my cherokee i run 4Hi on the roads when there slick otherwise with the boggers i go no where

[WhiteOut]

FML, I started a monster.

[Zombie]

I will stand corrected, I was playing arround tonight and braking with 4hi on did slow me down and resisted lock up betterthan in 2hi,  so that is a good thing.

so driving in 4x4 can help with braking.

but I still stand by my point that with worn out or most mud tires( I have heard some are very nice with snow, ice on the other hand...), and many all-terrain or all season tires,  winter driving is better with winter tires. 
I am sure most will agree with this.
And this is why I will still laugh a little when the 4x4 guys and gals say they don't need more siping in a tire(basically they are wanting a big blocky tire to look cool) because they know how to drive and it is a 4x4

FML, I started a monster.

don't worry, I find it interesting the number of different opinions out there and how the thread moved in different directions, I found out a few things, so it was worth it for me.

[RedDog]

South of Gasoline Alley on the way to Calgary a couple weeks ago: