Open Differentials vs. Traction Control vs. Lockers

[MOguy]

You are obviously not really reading anything I have been writing. If you just want to sit on your hands and not try to learn anything that is on you.

I agree that automatic REAR lockers suck. I hate them. I would never run one. An automatic FRONT locker however, when used in conjunction with a selectable REAR locker, is a fantastic combo. It is actually a LOT better at a lot of things than a front selectable locker. I wrote up lots about why and how a few pages back.

Remember, I own and drive both combos. That should tell you something. When I install the new front axle and locker in the flat fender soon, it will get another automatic front locker. I just spent 3 years building my LX45 from scratch. It is selectable/selectable. I was curious again after having this conversation with myself and others, if it was really 'better'. It really isn't in a lot of ways. It is functional, but it does have fairly large drawbacks. I can't really notice that many upsides to the front selectable over the front auto honestly. The next project I build will be automatic front again. If the LX45 wasn't full-time 4wd, I would seriously consider changing the front to an automatic locker.

We can get an inch thick sheet of ice, with no snow. in my experience Whenever two wheel spin at the same time, as if they are locked, the vehicle will drift sideways. With one wheel spinning you still have traction issues but at least you're more likely to move forward if you move it all. I don't want to be locked on ice.

 

[Metcalf]

We can get an inch thick sheet of ice, with no snow. in my experience Whenever two wheel spin at the same time, as if they are locked, the vehicle will drift sideways. With one wheel spinning you still have traction issues but at least you're more likely to move forward if you move it all. I don't want to be locked on ice.

Do what works for you.

In general, the front axle goes where you point it. There rear axle pushes the car straight because it is always pointed perpendicular to the vehicle centerline ( generally, not going to get into bad positive roll axis suspension setups ). Unlock the rear axle, and then the front axle isn't being pushed straight by the rear of the car. I've had my flatty up to about 45-50mph in very icy mountain up/down/around conditions in 4wd with the automatic front locker without issues. Beyond those speeds, I have always just popped it in 2wd. I have done that in ALL part time 4wd vehicles I have owned. I've never liked the understeer that 4wd open/open generally delivers at higher speeds. That is one thing that really annoys me in my LX45. At higher speeds I like being able to drive with the throttle a little. A limited slip rear axle is nice. I really like the old power-lok diff. They had just the right amount of 'help' in 2wd to stabilize things and prevent the one-wheel wonder thing, but it isn't so aggressive to get in the way like a spool or automatic REAR locker.

 

[MOguy]

Do what works for you.

In general, the front axle goes where you point it. There rear axle pushes the car straight because it is always pointed perpendicular to the vehicle centerline ( generally, not going to get into bad positive roll axis suspension setups ). Unlock the rear axle, and then the front axle isn't being pushed straight by the rear of the car. I've had my flatty up to about 45-50mph in very icy mountain up/down/around conditions in 4wd with the automatic front locker without issues. Beyond those speeds, I have always just popped it in 2wd. I have done that in ALL part time 4wd vehicles I have owned. I've never liked the understeer that 4wd open/open generally delivers at higher speeds. That is one thing that really annoys me in my LX45. At higher speeds I like being able to drive with the throttle a little. A limited slip rear axle is nice. I really like the old power-lok diff. They had just the right amount of 'help' in 2wd to stabilize things and prevent the one-wheel wonder thing, but it isn't so aggressive to get in the way like a spool or automatic REAR locker.

If your able go 45 we are talking about different conditions

 

[IdaSHO]

Clearly. And still missing the point of a vehicle walking sideways in limited traction situations when both tires on the same axle break traction.

Anyone that has been on ice with a locker knows that it is a recipe for disaster, even on flat ground.

I refuse to run auto-locker or spool for that reason, front or rear.

 

[Metcalf]

If your able go 45 we are talking about different conditions

Up to 45-50mph, in a variety of conditions. I've been on icy roads so bad, that if you stopped, the vehicle just got blown sideways in the wind.

I've tried both combinations personally. I don't why you don't seem to realize that.
I've driven on bad winter roads for decades. I've driven them with open, rear locked, front locked, selectable lockers, limited slips, etc.
I'm not coming to my conclusions lightly. I have tried a lot of different things over the years.

 

[Metcalf]

Clearly. And still missing the point of a vehicle walking sideways in limited traction situations when both tires on the same axle break traction.

Anyone that has been on ice with a locker knows that it is a recipe for disaster, even on flat ground.

I refuse to run auto-locker or spool for that reason, front or rear.

.....and yet, I've done it for years and years. I grew up in Idaho. I currently live in Colorado. I have traveled to just about every part of the US over the years. I have driven on bad winter roads all my life with just about every combination of lockers possible. Have you?

I currently own and drive a selectable/selectable vehicle AND I have a front automatic/rear selectable vehicle.

They both have some pluses and minuses, but I PREFER the auto/selectable combo overall. I have yet to find a situation where the automatic front locker has held me back including slick icy roads which seems to be the current focus. The FRONT axle goes where you point it if the rear axle is open. Most steering issues come from under-steering induced by the REAR locker. I typically use the FRONT locker first ( even in the selectable/selectable vehicle ) if needed, which is also opposite of the mainstream view. I've written up a lot of explanations on why I feel that works better overall.

 

[MOguy]

Up to 45-50mph, in a variety of conditions. I've been on icy roads so bad, that if you stopped, the vehicle just got blown sideways in the wind.

I've tried both combinations personally. I don't why you don't seem to realize that.
I've driven on bad winter roads for decades. I've driven them with open, rear locked, front locked, selectable lockers, limited slips, etc.
I'm not coming to my conclusions lightly. I have tried a lot of different things over the years.

I am talking about ice so bad when you can hardly make it away from your garage and you decide to call your boss and tell him you aren't coming in. This is when lockers can screw you.

If their is snow or anything to help with traction I would agree with you. If there is no traction more tires spinning just pulls you different directions, usually side ways.

 

[Happy Joe]

...I really don't like icy roads; 'though i have driven them since learning to drive...

I am talking about times when you can hardly make it away from your garage and your decide to call your boss and tell him you aren't coming in. This is when lockers can screw you.
If their is snow, than I would agree with you.

Southern Illinois and I expect Missouri, with their ice storms (freezing rain) is a bit of a special case.... Most places the problem is nearly invisible polished black ice (glare ice) and snow packed to form ice, then polished by non drivers spinning their tires.
I have never been able to not get out of the driveway; "though I have broken trail, in very deep snow, so the rest of the people on the street had a chance once they could get their CARs, SUVs and pickups out of their driveways...

Used to keep a box of short sheet metal screws in the CJ-5 to use on temporary studs when driving up frozen flooded trails and across frozen rivers (where you have to climb over the ice shelf at the edge or out of the hole if you break through) 4wd by itself was never adequate nor was any all terrain tire that I ever tried..

Even after having the rear auto locker try to kill me, a number of times, I drove it for decades; you learn to watch for the things that indicate danger. (Like sunny state licence plates).
When the tires get quiet on the highway; prepare to get turned sideways/hold on and pray (its already too late to do anything).
Mostly, you just have to have some situational awareness (and be able to dodge the non drivers sliding around out there).... I will say that the tendency so slide sideways/downhill on black ice soured me on auto lockers.

In winter, I liked off roading in really deep snow best If you can achieve flotation its a great experience; you can make waves in the powder but have to find a shallow place to stop or you become instantly high centered.
Not yet seen an unlocked vehicle able to do it, nor a large diesel pickup/expedition rig (too heavy, IMO). If they can get to the trail head the snowplow berm at the side of the road usually stops them. Floating a vehicle over deep snow in town is likely a very BAD idea.

Enjoy!

 

[IdaSHO]

Yep, and its that extra BS with auto-lockers that is a big safety problem.

With simple open diffs (or unlocked selectable) if you hit ice or a slick spot, one tire will spin, and you will loose a bit of forward motion.
Locked, as you mentioned, the vehicle will walk sideways, or worse. Hit a slick spot with one tire and not the other on a locked front end
and the vehicle will effectively torque steer. As the tire that still has traction will keep pulling, and depending upon which way and how far the tires are turned.....

This is all to common in snow country, especially on highways. Spotty ice/snow roads with completely unpredictable traction.
I've pulled more people out of the ditch because of locked axles on snowy/icy trails and roads, even when traveling snow speeds.
Open diffs? Generally they are traveling too fast, beyond the conditions.

An auto-locker also has a tendency to remain locked on ice. Bad news for any turns.
You are already on ice, now you have a vehicle that will push/understeer, potentially right into the ditch,
which makes the claim that the front axle always goes where you point it completely false.

 

[Metcalf]

I am talking about ice so bad when you can hardly make it away from your garage and you decide to call your boss and tell him you aren't coming in. This is when lockers can screw you.

If their is snow or anything to help with traction I would agree with you. If there is no traction more tires spinning just pulls you different directions, usually side ways.

Been there, done that. I am the guy that shows up to work on days to locked doors because the roads where 'so bad' for everyone else.
So basically you would rather go nowhere vs having a chance to go somewhere?

I agree a REAR full time locker can be a headache. That is why I don't run one. The front axle is a different story.

If all you care about is one specific situation you are not comfortable with, by all means do whatever works best for you.
I am saying all around......including the very type of situations you are concerned about....I prefer an automatic front and selectable rear.
I own and drive both.

 

[Metcalf]

Yep, and its that extra BS with auto-lockers that is a big safety problem.

With simple open diffs (or unlocked selectable) if you hit ice or a slick spot, one tire will spin, and you will loose a bit of forward motion.
Locked, as you mentioned, the vehicle will walk sideways, or worse. Hit a slick spot with one tire and not the other on a locked front end
and the vehicle will effectively torque steer. As the tire that still has traction will keep pulling, and depending upon which way and how far the tires are turned.....

Yes, the tires go where you point them. REAR tires always want to go straight regardless of the locker. Adding a rear locker, be it an automatic, spool, or whatever, will cause the vehicle to understeer more. Nobody has been debating that. That is why I like a rear selectable locker.

The front tires on the other hand, go where you point them. If you think you can drive on icy road with slipping and sliding tires with ZERO driver input, I got nothing for you. I can tell you from practical experience over many years, that a front automatic locker is NOT the death sentance that many make it out to be. Been there, done it, didn't just read about it. Once you get beyond focusing on the dreaded icy road situation, it gets even better and has some real advantages over the a front selectable.

This is all to common in snow country, especially on highways. Spotty ice/snow roads with completely unpredictable traction.
I've pulled more people out of the ditch because of locked axles on snowy/icy trails and roads, even when traveling snow speeds.
Open diffs? Generally they are traveling too fast, beyond the conditions.

An auto-locker also has a tendency to remain locked on ice. Bad news for any turns.
You are already on ice, now you have a vehicle that will push/understeer, potentially right into the ditch,
which makes the claim that the front axle always goes where you point it completely false.

Really? Have you tried it? Lets start there. Have you PERSONALLY put thousands and thousands of miles on an automatic front locker with rear a rear selectable combo?

I'll wait......

What mechanism in the vehicle is going to make the vehicle push over and drive through the front tires when they are turned in a different direction? There are two possible options. 1. The vehicle was going too fast in the previous direction with too much momentum. It won't really matter what you have if you can't drive and blow through a corner. 2. The REAR axle of the vehicle is pushing too much, because those tires always point straight ahead. I've never told anyone to run a full time rear automatic locker. I actually dislike that combo a lot.

In certain situations it can be really nice to be able to drive JUST the front wheels. This isn't too common in the 4wd world, but it is possible. This helps eliminate ANY rear axle push.....even just the push from an open diff rear axle. This can make the vehicle much more maneuverable.

If all you guys want to want to do is obsess about driving around on super extra ultra greasy super slick winter roads by all means go ahead.
I'm not going to learn anything new listening to it.

 

[Metcalf]

I mean......if you want to obsess about winter roads and sliding around....

If you just run 2wd with an open differential then you are going to probably have 3 other tires to hold your vehicle in place from slipping sideways.
That sounds like the safest option by your current logic.

 

[IdaSHO]

Its pretty simple logic, that you seem to ignore. Perhaps as all you seem to want to do is argue for the sake of argument?
You certainly seem to be stuck in a one-sided ******** swinging contest. Maybe consider dropping the attitude and considering other perspectives....

A locked front when turned forces one of the tires to slip as one of the tires cannot match road speed.
An open diff on the other hand can match road speed, and limit slip better.

I prefer to have the ability to TURN, thank you very much.
And that requires the steer axle tires to match the road speed and retain grip.

Mobbing thru deep mud/snow is a completely different discussion, FYI, as we are talking about retaining grip, not slinging earth to find grip.

 

[Buliwyf]

When you only have glare ice, switch back to 2wd. The front hubs unlock, and the front locker disappears.

You don't need 4wd to keep up with a Honda Odessy minivan. That's sad. That's really sad. Hardpacked icey sleet nonsense that I drove through perfectly fine, with a POS 1993 Mercury Topaz. That I bought for a sack of tacos, when I was 15.

Slip sliding on the freeway? That's just plain too much throttle or speed. Don't blame lockers for operator error or poor tire choices. The only reason I use 4wd above 35mph is to smooth out a bumpy dirt road. Unpowered tires have more side bite than driven tires. All you need to maintain hwy speed is light throttle and one driven wheel.

If you really want to use 4wd on ice, at speed, then a selectable front is best. But it won't match an auto up front off road, or be as reliable. That's the trade off.

 

[Saint Nick]

Slip sliding on the freeway? That's just plain too much throttle or speed. Don't blame lockers for operator error or poor tire choices. The only reason I use 4wd above 35mph is to smooth out a bumpy dirt road. Unpowered tires have more side bite than driven tires. And all you need to maintain hwy speed is light throttle and one driven wheel.

Couldn't agree more. I drove a 350+bhp 2wd Sierra Cosworth in all conditions on the road, and any slides were induce when my right foot become to heavy!

Nick