4x4 question
 

Iam new here and dont want to start a thread just to ask a question , so here goes
My truck is F150 2016 4x4 XLT
My question is , when using 4 wheel drive do you pull out the posi tracktion button also ? or just turn the knob to 4x4 H ?

Generally, 4X4 is sufficient unless you're in deep doo-doo. Locking the rear does just that and doing so in anything less than very low traction situations can cause expensive noises. The only time I've used the locking rear on my Lariat was in moderately deep mud with slippery, wet rocks.

So if you only turn knob to 4H are all 4 wheels pulling or just three ??
Does the positraction knob make all 4 wheels pull ?

In 4H equal power is sent to all 4 wheels. In moderately low traction situations - loose dirt, moderate snow, etc. a wheel will slip here and there. Front and rear axles each get 50% of the available power. Both front and rear differentials behave as open diff's sending power to the wheel with the least traction. If a front OR a rear wheel starts to spin it will get the most power. In theory, you could get one front and one rear wheel in the air and be stuck. Happens all the time in big rocks with open diff's.
One thing, it is NOT positraction. Positraction refers to a system that locks up when it detects one wheel on an axle starting to spin but behaves as an open diff at all other times - otherwise it would be difficult to go around corners. Ford's system is a locking differential. When engaged, both rear wheels are locked together. On dry pavement and high traction surfaces it WILL be difficult going around corners. Each rear wheel receives 50% of the power going to the rear all the time. That's why you don't want to use a locked rear in snow and ice unless you like going sideways a lot.

It ONLY functions on the rear axle.

THANKS for your time and info

Heya Dawg, welcome to FTE! :-drink

Just so you understand how forums work, asking your own question and starting your own thread is EXACTLY how forums are supposed to work. Please don't hijack another users thread to ask your own questions about your truck. We can only learn from each other if we have separate threads addressing problems, not one single thread where everyone posts and asks whatever they want regarding the problems they are having with their truck. :-X22

Can you imagine a thread like that? It wouldn't be helpful or useful at all. ;)

Stewart :-jammin

What ever you do DO NOT pull out the knob in any position and drive on dry pavement. You can and will damage the internals of the rear differential.

I engage the 4x4 once in a blue moon only when the road is absolutely straight, perhaps every 5,000 miles or so, so that the components are lubed.

I agree with the above.. do NOT engage the lock (pulling it out) unless the traction is loose. I only engage it on sand or snow, never anywhere else.

above a certain speed the diff lock disengages automatically. Only usable at low speeds. Assume this is an inbuilt safety feature so you don't lose control of the vehicle.

True. The locking diff will disengage above 25 mph in 2 wheel drive 4 wheel auto and 4X4. BUT it won't disengage until 62 mph in 4X4 low range. Don't know about you but I'm not inclined to test that one out. Sixty two mph in low range with a locked rear?!? Not me!

Also, the Advanced Trac system can take over control of the locking diff in certain situations.

If you live in Snow country and freezing conditions in parts of the country, and if you have a Black ice conditions on the road do not engage 4H on the road. You will skid if you do.

This not really true in today's trucks. The fords have a "posi-trak" system, they just use the brakes to stop the slipping. No real difference here between clutches in the diff (friction material) and brakes (friction material) other than the brakes can indeed get over temp (if you've got a lot posi requirement)and the system will revert to open diff for a few minutes till they cool down to temp.
You can't get two wheels in the air and have them spin freely. The trucks have both two wheel spin control and one wheel spin control (which is always active). This effectively stops one wheel spin (which the truck can sense) and hits the brakes on the free spinning wheel. There is still some slippage but the system works well. Locking the rear diff stops all slippage on the rear for precision control when needed. The front will still engage one wheel traction control.

So the quick answer is yes, power is (almost) always sent to all four wheels when needed in 4 high.

I thought that would be for the AWD, not the 4WD...

This is how the system works for 4 high. 4 low is not quite the same as all the nannies are disabled except for one wheel spin control.
Not 100 percent sure on the AWD as there is a clutch used in the transfer case that I haven't really delved into. I'd presume the two wheel spin control (front speed vs rear speed) is what sends the signal to the clutch.

The F150 doesn't have the intelligent 4wd system. The closest you can get is the terrain management system on the Raptor. The 4A does use an electric TOD transfercase that takes its input from wheel speed, engine load % and transmission output speed. The system you are referring to is the advance trac system which is designed to increase control and stopping ability of the truck. It will cut throttle and you will see engine power reduced message on the gauge cluster. Pressing and holding the traction control button for 10 seconds disables TC and AT but doesn't bypass RSC, to bypass all put it in 4Lo.