Limited Slip in front
01-12-2014, 09:45 PM
#51
Only if you don't have limited slip of mechanical or electronic nature. We have electronic limited slip where braking of the slipping wheel forces torque to the opposing wheel. Downfall to electronic as mentioned is overheating of the brakes where the electronic limited slip will be disabled until they are cooled. This is where it's nice to have the locking rear axle when in the deep stuff.
Last edited by Mike Up; 01-12-2014 at 09:57 PM.
01-12-2014, 11:03 PM
#53
TTV6>V8
Wish I could say the same about a guy like you who just needed to get childish shot in a few days after my comment was made.
Now **** off and take your BS elsewhere.
01-12-2014, 11:06 PM
#54
TTV6>V8
Oh and thanks Mike, that wasn't directed at you. I did some reading up on it and watched the videos posted. I just figured if there was binding then the wheels MUST be locked. And I was wrong :/
01-12-2014, 11:15 PM
#55
Senior Member
Yes, thank you for reiterating that. I'm pretty sure I already apologized and thanked the guys for helping me understand my mistake. And yes I WAS admittedly ignorant and I'll do my best to make sure it doesn't happen again.
Wish I could say the same about a guy like you who just needed to get childish shot in a few days after my comment was made.
Now **** off and take your BS elsewhere.
01-13-2014, 01:22 AM
#57
Senior Member
i really enjoyed this, Al. thank you, sir.
It's funny that you say that. Not poking fun, it's just funny considering.........
Extreme Traction-Control Test - YouTube
Extreme Traction-Control Test - YouTube
06-13-2017, 04:39 PM
#58
FORD lifer
Thread Starter
FYI guys - after living with it for a couple of months, I've decided it's a great mod - other than the cost there is no downside.I've driven it across the country and back, through the muddy landfill, through snow, and on dirt and loose gravel. You do feel it up there, it's a little heavier when it's engaged, but the traction is awesome.I just turned 117,000 miles yesterday, because one of the kids graduated from college and is going to work in Michigan, so I put 3300+ miles on the truck this week, 14.5 mpg pulling the 6' x 12' U Haul trailer there, and 20.2 mpg on the way back, with no trailer.
05-01-2018, 01:03 AM
#59
Hey all,
So yes I'm reviving an ancient thread, because I came across it in my search for something related, and I'm sure other people will come across it as well.
Lots of back and forth here in this thread, a little bit of anger haha, and unfortunately, a good deal of inaccurate information. I looked and many of the posters are still active, so I might as well chime in on some of the hot points.
For our discussion, let's firstly eliminate any talk of either Limited Slip Differentials / Torsens, and Traction Control (braking to emulate a limited slip). We're talking about basic 4x4 with open diff in both the rear and the front.
In a 4x4 F-150, when in 4Hi, all four wheels are engaged. Period. When in 2Hi, both rear wheels are engaged. Period.
Any talk of "one wheel drive" when in 2Hi is wrong. Any talk of "two wheel drive" (one rear, one front) when in 4Hi is wrong. Any talk of "three wheel drive" when in 4HI, rear diff locked is wrong. It's nice and easy: 2Hi, two rear wheels driving forward. 4Hi, all four wheels driving forward.
As for open diffs, probably the single most frequently made statement, which is also incorrect is something to the effect of "In an open diff, power goes to the wheel with least traction". That is not correct. In an open diff, power always goes to the left and right wheels equally, 50 / 50, all the time. 100% of the time. Any talk of power "being routed to the wheel with least traction" is wrong. Any talk of a traction-adding system like Traction Control "routing power to the other wheel with traction" is wrong. There is no "routing of power". An open diff splits power 50 / 50 to the left and right wheels 100% of the time. That's how it works.
That's not to say that you won't get a one-wheel peel. Or that you can't get one wheel spinning on ice while the other just sits there. Of course you can. But it has noting to do with "routing power" to one wheel or another. Put simply, the power that goes to both wheels (EQUALLY) is the amount of power that the tire with the least traction can contain without slipping. So for example, if you're in 2Hi, and on dry pavement, your rear tires can receive 100% of the power without slipping. Both rear tires will get a 50 / 50 split of that power. Let's go to the opposite extreme. One rear wheel on ice, the other rear wheel on pavement. We know the power that goes to both wheels (equally) is the amount that the tire with the least traction can contain without spinning. Let's say for the sake of argument, the tire on ice will slip at 5% of the total power, since it only takes a little power to spin a tire on ice. Well the other tire will only get 5% power as well (since it's always equal). The tire on ice gets its 5% power and starts to spin on the ice, the tire on pavement gets it's 5% power and just sits there without spinning, because 5% power is not enough power to drive the truck forward. You're stuck. The tire on ice spins wildly, the tire on pavement sits there useless.
The front with an open diff is no different. It behaves exactly the same as the rear. Both front tires receive 50 / 50 split of the power, 100% of the time. If one wheel has less traction, the power delivered to both front wheels is reduced just like it would be in the rear. If both tires have traction, they're both driving forward.
So for example, if both rear tires were on ice, and both front tires were on pavement, you'd easily pull yourself out of that situation. Both front tires will pull you out.
Traction Control as other have mentioned, helps with the open diff situation. It "simulates" traction of the spinning wheel, to bring total power (to both wheels) back up. For our ice example, if one rear tire was on ice, and the other on pavement, the power is reduced to 5% because that's what it takes to spin the tire on ice. Traction Control kicks in and applies the brakes to the tire on ice. That simulates more resistance (as if it's not on ice). Power (to BOTH wheels) goes up until the tire on pavement receives enough power to move the truck forward.
Yes, I know some of the videos posted above talk about power being "routed to the wheel with least resistance". That's just because that's how people visualize and understand it. But that's not actually how it works.
As for locked diff, that's the beauty of it. The shortcomings of open diff go away. The whole thing about "reducing power to the amount where one wheel slips" goes away. Power is not reduced. All the power goes fully to the axle and both wheels spin regardless of the traction the other one has. That's why, for example, locked diff is great in mud. Just floor it and you know power is going to the entire axle, both wheels spinning at full speed and clearing mud out of the treads.
Anyway, sorry to revive an ancient thread, but if even one person reads this and has a better understanding of how it all works, and even better if that prevents them from getting stuck, then it's worth it.
So yes I'm reviving an ancient thread, because I came across it in my search for something related, and I'm sure other people will come across it as well.
Lots of back and forth here in this thread, a little bit of anger haha, and unfortunately, a good deal of inaccurate information. I looked and many of the posters are still active, so I might as well chime in on some of the hot points.
For our discussion, let's firstly eliminate any talk of either Limited Slip Differentials / Torsens, and Traction Control (braking to emulate a limited slip). We're talking about basic 4x4 with open diff in both the rear and the front.
In a 4x4 F-150, when in 4Hi, all four wheels are engaged. Period. When in 2Hi, both rear wheels are engaged. Period.
Any talk of "one wheel drive" when in 2Hi is wrong. Any talk of "two wheel drive" (one rear, one front) when in 4Hi is wrong. Any talk of "three wheel drive" when in 4HI, rear diff locked is wrong. It's nice and easy: 2Hi, two rear wheels driving forward. 4Hi, all four wheels driving forward.
As for open diffs, probably the single most frequently made statement, which is also incorrect is something to the effect of "In an open diff, power goes to the wheel with least traction". That is not correct. In an open diff, power always goes to the left and right wheels equally, 50 / 50, all the time. 100% of the time. Any talk of power "being routed to the wheel with least traction" is wrong. Any talk of a traction-adding system like Traction Control "routing power to the other wheel with traction" is wrong. There is no "routing of power". An open diff splits power 50 / 50 to the left and right wheels 100% of the time. That's how it works.
That's not to say that you won't get a one-wheel peel. Or that you can't get one wheel spinning on ice while the other just sits there. Of course you can. But it has noting to do with "routing power" to one wheel or another. Put simply, the power that goes to both wheels (EQUALLY) is the amount of power that the tire with the least traction can contain without slipping. So for example, if you're in 2Hi, and on dry pavement, your rear tires can receive 100% of the power without slipping. Both rear tires will get a 50 / 50 split of that power. Let's go to the opposite extreme. One rear wheel on ice, the other rear wheel on pavement. We know the power that goes to both wheels (equally) is the amount that the tire with the least traction can contain without spinning. Let's say for the sake of argument, the tire on ice will slip at 5% of the total power, since it only takes a little power to spin a tire on ice. Well the other tire will only get 5% power as well (since it's always equal). The tire on ice gets its 5% power and starts to spin on the ice, the tire on pavement gets it's 5% power and just sits there without spinning, because 5% power is not enough power to drive the truck forward. You're stuck. The tire on ice spins wildly, the tire on pavement sits there useless.
The front with an open diff is no different. It behaves exactly the same as the rear. Both front tires receive 50 / 50 split of the power, 100% of the time. If one wheel has less traction, the power delivered to both front wheels is reduced just like it would be in the rear. If both tires have traction, they're both driving forward.
So for example, if both rear tires were on ice, and both front tires were on pavement, you'd easily pull yourself out of that situation. Both front tires will pull you out.
Traction Control as other have mentioned, helps with the open diff situation. It "simulates" traction of the spinning wheel, to bring total power (to both wheels) back up. For our ice example, if one rear tire was on ice, and the other on pavement, the power is reduced to 5% because that's what it takes to spin the tire on ice. Traction Control kicks in and applies the brakes to the tire on ice. That simulates more resistance (as if it's not on ice). Power (to BOTH wheels) goes up until the tire on pavement receives enough power to move the truck forward.
Yes, I know some of the videos posted above talk about power being "routed to the wheel with least resistance". That's just because that's how people visualize and understand it. But that's not actually how it works.
As for locked diff, that's the beauty of it. The shortcomings of open diff go away. The whole thing about "reducing power to the amount where one wheel slips" goes away. Power is not reduced. All the power goes fully to the axle and both wheels spin regardless of the traction the other one has. That's why, for example, locked diff is great in mud. Just floor it and you know power is going to the entire axle, both wheels spinning at full speed and clearing mud out of the treads.
Anyway, sorry to revive an ancient thread, but if even one person reads this and has a better understanding of how it all works, and even better if that prevents them from getting stuck, then it's worth it.
05-01-2018, 08:26 AM
#60
FORD lifer
Thread Starter
Well, you surely revived this zombie thread of mine.:laughing
Not to be too critical, but your theory is mostly wrong.
Take a vehicle with open differential to a drag strip, and punch it, then earnestly tell us that both rear tires get the same amount of traction.
Come borrow my dump trailer, we will put 5000 lbs of rock into it, then we will go to a dirt road, and do some starting and stopping. I then would like you to explain the one-wheel peels you get.
And last winter, I pulled out two people who were stuck in deep snow, they had all season tires, and they had one tire spinning on the front, and one spinning on the back. That doesn’t happen, right?
Lastly, put one side of your truck on the dry, and the other two tires on ice, step on it, and see what happens. I can tell you for sure that if you have a good LS you will simply pull away.
Too funny!
Not to be too critical, but your theory is mostly wrong.
Take a vehicle with open differential to a drag strip, and punch it, then earnestly tell us that both rear tires get the same amount of traction.
Come borrow my dump trailer, we will put 5000 lbs of rock into it, then we will go to a dirt road, and do some starting and stopping. I then would like you to explain the one-wheel peels you get.
And last winter, I pulled out two people who were stuck in deep snow, they had all season tires, and they had one tire spinning on the front, and one spinning on the back. That doesn’t happen, right?
Lastly, put one side of your truck on the dry, and the other two tires on ice, step on it, and see what happens. I can tell you for sure that if you have a good LS you will simply pull away.
Too funny!