I see what you mean.

I assume its under 25 since he's turning in a parking lot.

 

its got traction control.

 

Not something I'd want on icy roads... 4x4 & icy roads go together like water and oil.

 

That auto 4 button was a joke. It was in my GMC Sierra anyways.You were engaged on dry roads & when there was snow on the road it was disengaged.It just did not work.

 

Just like everyone is saying, the front axle is binding up. This happens because there's not enough slippage. Many say that 4WD shouldn't be engaged unless there's enough slippage to keep that from happen. This will damage your drivetrain. This is happening because usually on trucks, they have much better tires than crossovers or cars, and they can bite better though light snow. If it's a powdered snow, I use 2WD. If it's slush, where the road is really slick, I use 4WD.

If it's a toss up between dry and slick roads, I engage 4WD on the straight paths and disengage when turning.

As far as the front differential going from rocking, this can make sense. You have to drive to get the truck to completely lock in the axle. Rocking it, after engaging while parked, seems like a very destructive motion. Engage before you get stuck.

Auto (full-time) 4WD is not everything it said to be. I had it in the Sport Trac and I often used the 4Hi Part Time. The reason is for the automatic 4WD to engage, the computer had to see tire slippage. Well as anyone knows, as soon as wheel slippage occurs, it's to late. Ford says it only takes milliseconds but I have had problems because it allowed slippage before engaging. So if I know I'm in an area that would need 4WD, I use it. IMO, Auto (full-time) 4WD is for women who really don't understand the function and correct usage of Part-Time 4WD.

Also the Sport Trac had open differentials but had limited slip on both axles through BLSD. That is where the brakes are used to function the axle as LS. Very effective. It was part of the traction control. Through different selections, traction control control could be turned off when wheel spin is needed for sand and snow. It however had a mode that left only the braking Limited Slip ****ion (Wow, censoring f-u-c-t) on, it was great. Now the F150 has the same system but we have mechanical LS rear differentials also. I don't really know how this works with the LS Rear differential. However I noticed in the manual that when you turn off traction control, you also turn off Brake LS. I don't like this because I would want to use this for the open differential on the front axle. Perhaps Ford does use a mechanical LS on the front but I never read of this.

Auto 4WD just engages electronic clutches to engage the front axle. When there's a difference in speed between them, the clutches slip. I don't really know if it ever locks in 100% with no slippage as it would have to keep detecting slippage with the sensors.

As such Auto 4WD isn't good for anything but wet roads IMO or the wife's/girlfriend's use of it.

 

From all you answers, it was just like I thought. I am used to the Xploders 4WD system..which is more of an Alltrac someone mentioned.

I did turn off the 4WD as soon as I noticed the hopping.

Sorry, I failed to mention: 2010 XLT!

 

My lifted 2010 Platinum pops like a mf'er in the snow. Even with plenty of snow to allow slip.And its a pretty loud POP. Its worrying me! I try to turn off 4wd in turns but even some not so tight turns make it pop. What are the differentials on the front n rear on non-fx4, non-raptors? Arent mine limited slip? Shouldnt they be slipping rather than popping? lol! Ugh!!!

It was a piece of junk, but my 2006 Jeep Commander Limited (previous vehicle) seemed to have a well sorted 4x4 system that never hopped or popped... but i think it had electronic LSDs front n rear??? It was the Quadra Trac II i think. But, my dad always said, the more gizmos you add, the more there is to break.

 

If you have a LS, it would be rear only. Front is always an open diff. LS in front would cause problems.

 

well whatever it is, it pops like crazy loud... not the happiest on how easy it binds. Im use to most of my previous 4x4s hopping, lurching, etc when turning but this is the first one to POP.

Wouldnt an open diff keep it from popping. I always get confused on differentials!

 

True 4wd pickups have always gotten in a bind in turns, when locked into 4wd. When I was a kid in the early 70s, our pickup would bind and buck everytime we got out on the highway after being at the farm and in 4wd. That is when Dad would remember and take it out.
AWD drive and other variations of 4wd have vicious clutches in the transfer case to slip so the front and rear axles don't bind.
I have a 2006 GMC 3500 and it binds as all of them do on dry pavement, or an area of high traction.

The reason is because when you go into a turn, the front wheels have to travel different distances from one another and also fron the rear tires. It is called the Akerman Theory (not sure of the spelling). The arc that the outside front wheel has to travel is greater than the inside wheel. On an open differential or LS, this is not an issue if there is one axle. However, when you add the rear axle, you add two more wheels that are LOCKED to the front axle with no viscious clutch to give. So therefore, you have 4 tires locked together trying to go different speeds. If the traction is to great, you bind and when it jumps or hops or bucks, that is the energy being released from the bind.

It is completely normal and if you turn very sharp on dry pavement for very long, you could break something.
This is the way it has been since 4wd trucks have been invented. Not a new concept, and that just means everything is working as it should.
Viscious clutch type systems are great for their intended purpose, which is light duty use. These F150s are made for heavier duty use, so they have locking transfer cases that don't slip.

I don't use 4wd unless there is snow or mud on the ground, or I need to go straight or am pulling something out. When I get to where the roads are clean, I pop it out.

 

In short, its binding front to rear not side to side.

 

That's right!

Y'all .... thje open poster is on a level snow covered parking lot making turns, the rear always track inside the front in a turn, but the transfer case of a part time system makes both front and rear drive shafts turn same speed, while the front has further to travel around the turn ..... something has to slip.

Tires slip on snow.

Do it on dry pavement and you can seriously get into expensive repairs.

Yes, a rear locker will agrevate it, .... a limited slip not so much unless you jump on the throttle heavily.

If you don't need the 4WD, use 2WD.

 

Like I said, I know it's going to buck in the turns n understand why... but is everyone getting an audible pop? Is that pop the IWE disengaging/reengaging? That's all that was concerning me. I can't remember if it did this last year before the 6" lift. I dont think it was as sensitive before the lift. Oh, and the front driverside did pop, like u said, when I took off from a traffic light (no turning involved).

Thanks for all the help as usual !!

 

You should take into consideration your tires. If they are "biting" the snow real well, or rather if there is not much snow and its"biting" thru the snow to the pavement then its getting good traction and not allowing it to slip. I noticed that with my toyo m/t's on snow that wasn't that thick would pop when turning, but never when going straight.

 

If you are lifted, the pop may be a CV joint.