4A acting like 4H, binding while turning on dry pavement

[crenca]

Here is why, all of there parts are turning anyway as there are no hub disconnects. One of our engineers said our awd works exactly the same as the 4a system on our offroad cars.

I'm going from memory here, but I recall Audi/VW had a system about 15 years ago with friction clutch packs at the output of (what essentially is a front drive layout) the transmission (i.e. before the prop shaft), as well as both outputs of the rear diff. The computer would disconnect the drive shaft and of course two rear axle shafts when not routing torque the rear diff. This was not for 'wear', but an effort to eak out bit more gas mileage (due to less rotating mass on the drivetrain).

I don't think this solution lasted very long, I suspect too much $ and parts for too little benefit. Of course the rear diff friction packs are still very much a thing for variable torque distribution across rear axle (hubs are are always 'connected' of course)...

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[DarthLincoln]

Opinions aside (they’re worth what you paid for them) Ford’s own service manual says 4A is fine for dry pavement:
”(4A) is appropriate for all on-road driving conditions, such as dry road surfaces, wet pavement, light snow or gravel.”

Also If it wasn’t intended for dry pavement, Ford would not have made 4A the default mode in the Advanced 4x4 T-case Broncos for Sport mode which is definitely for dry surfaces.

That’s the whole point of A4WD - it operates as 2WD and only engages the other axle as needed due to detected wheel slip or handling/stability needs.

OP, good luck with the service repair. If the binding is intermittent, that‘s more likely a hardware issue.

 

[Pbethel]

My late wifes 2007 Sport Trac Had 4A, 4H, and 4L. Even then 4A and traction control worked very, very, well on icy roads. My biggest gripe about it was there was no 2WD option
So Ford has been in the AWD game quite a while.

 

[Pops]

I’ve a question about this.

does the off-road info telling thing on the dash, the one that shows power distribution to the front or all four wheels, show real-world?

My 4A seems to sometimes grab (trails) and sometimes does not (pavement), but the power distribution indicator always shows power to all wheels.
I used to worry about making sure I had 4A off when not thinking I may be able to use it.
Thanks well in advance!

 

[VirginiaHeritage]

I’ve a question about this.

does the off-road info telling thing on the dash, the one that shows power distribution to the front or all four wheels, show real-world?

My 4A seems to sometimes grab (trails) and sometimes does not (pavement), but the power distribution indicator always shows power to all wheels.
I used to worry about making sure I had 4A off when not thinking I may be able to use it.
Thanks well in advance!

Pops, my ‘25 power distribution display always looks the same in 4A at any speed. It shows the front driveshaft and axles moving with a corkscrew-like animation.

 

[crenca]

does the off-road info telling thing on the dash, the one that shows power distribution to the front or all four wheels, show real-world?

I have asked this question as well (is it real time data, or simply a "simulation" that does not actually report any rea time data), but techs like @Ducati1098 can not see the code behind it to confirm/deny. I suspect it is simply an indication of the actual programming of the system.

That said I do believe it to be accurate. There is a sweeper I hit at about 45 regularly. I can approach it in 4th gear (2.3L MT SAS) at a steady speed, so the "power distribution" indicates torque to rear axle only. If I apply non-trivial throttle in the middle of the sweeper, the gauge indicates torque suddenly being applied to front axle, and the butt-o-meter confirms the slight torque steer and the front end being "pulled" through the turn.

Another example: I am daily on sandy two tracks. I will be down in an arroyo in 4A (traction/stability control off) and threading my way through plant life which involves near-to-maximum steering angles. The gauge indicates little-to-none torque being distributed to the front axle when I'm at these extreme steering inputs, and sure enough I am bogging down with rear tires digging in. I switch to 4H, and the front end starts doing its part and I'm able to pull through the sand.

Pops, my ‘25 power distribution display always looks the same in 4A at any speed. It shows the front driveshaft and axles with a corkscrew-like animation.

The gauge he is referring to disappeared starting the MY25 year. The MY24 and older gauge shows rear-to-front axle torque (not speed) differentiation in "real time" - it's under the "off road" gauges...

 

[Valhalla]

Mine only adds front when power is applied.

 

[Ducati1098]

I have asked this question as well (is it real time data, or simply a "simulation" that does not actually report any rea time data), but techs like @Ducati1098 can not see the code behind it to confirm/deny. I suspect it is simply an indication of the actual programming of the system.

That said I do believe it to be accurate. There is a sweeper I hit at about 45 regularly. I can approach it in 4th gear (2.3L MT SAS) at a steady speed, so the "power distribution" indicates torque to rear axle only. If I apply non-trivial throttle in the middle of the sweeper, the gauge indicates torque suddenly being applied to front axle, and the butt-o-meter confirms the slight torque steer and the front end being "pulled" through the turn.

Another example: I am daily on sandy two tracks. I will be down in an arroyo in 4A (traction/stability control off) and threading my way through plant life which involves near-to-maximum steering angles. The gauge indicates little-to-none torque being distributed to the front axle when I'm at these extreme steering inputs, and sure enough I am bogging down with rear tires digging in. I switch to 4H, and the front end starts doing its part and I'm able to pull through the sand.

I may be able to datalog it in FDRS depending on which PIDs are available, but to be honest I’ve never looked.
I’m fixing a few things on my Bronco right now but when I’m done, if I remember, I’ll take a look.

But I agree and would guess that the gauge showing the power distribution is definitely real and accurate.

 

[SkyKing]

Unless I needed it I wouldn't run around all the time in 4A or 4H, especially not on dry roads. There's no reason to.

from what I understand, there is no reason not to. Doesn't affect gas mileage because unlike old-school locking hubs, the front axles and driveshaft keep spinning in 2H (they just don't get power). Your tires are still locked to the front axles and driveshafts and making them spin, even in 2H. The Bronco leans toward rear wheel drive in 4A while the Bronco Sport leans toward front wheel drive in 4A.

 

[Brian_B]

Bronco Sport leans toward front wheel drive in 4A.

This is true, but remember the Sport has full AWD with individual tire vectoring - Bronco AWD is just Front/Rear only with full open diffs

 

[SkyKing]

This is true, but remember the Sport has full AWD with individual tire vectoring - Bronco AWD is just Front/Rear only with full open diffs

This is true, but remember the Sport has full AWD with individual tire vectoring - Bronco AWD is just Front/Rear only with full open diffs

I own a Sport Badlands for my kids. Alto Blue with every option, plus some 245 BFGs. It's great car with impressive offroad tech. And fast as sh!t with 2.0. Couldn't find that in a CRV or Rav 4 even though they may be better "cars." Sorry, getting off topic.

 

[MilesTeg]

My '03 explorer didn't even have a 2H mode. It had only 4A, 4L, and 4H. It went 200k miles with no problem, other than being somewhat annoying at times.

If an ancient 4A system works fine being engaged 100% of the time with no option to disengage, I'm not worried about a modern one on dry pavement. I still use 2H for the better mileage though =P

 

[Valhalla]

I own a Sport Badlands for my kids. Alto Blue with every option, plus some 245 BFGs. It's great car with impressive offroad tech. And fast as sh!t with 2.0. Couldn't find that in a CRV or Rav 4 even though they may be better "cars." Sorry, getting off topic.

Dealer gave me a base sport during some recall work. It was a turd! Glad to hear higher trims don't suck.

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