Use of 4×4 modes on dry, non-slippery surfaces, and somewhat related questions about G.O.A.T. modes…

[Boxer4]

but I think Sport actually defaults to 4A if available

It Does

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[da_jokker]

Put simply, NO you should not use 4H/4L on any surface that does not allow for good tire slippage. Do not confuse this with lockers, we are talking about the transfer case and it locking the front and rear drive shaft together.

Believe it or not, but going down the road your front axle and your rear axle do not spin at the same exact rate. Especially when you're turning. So locking the front axle to the back axle, which is required both a turn of the exact same speed, isn't really possible without slippage and puts extra tension on the drive train.

4A is an entirely different topic. When you place a Bronco into 4A, it is not going in to four wheel drive. It stays in two wheel drive until the computer senses wheel slippage between the front and the back and it automatically engages the transfer case clutch to distribute power evenly between the front and the back. So it is okay to run in 4A since you'll never actually be in four wheel drive unless you're slipping.

 

[da_jokker]

It has been stated multiple times, that Baja mode is not the same as sport mode and should not be used on the pavement. Baja mode changes You're steering, breaking, traction control, and torque modes of the Bronco. The adjustments it makes are unsafe on pavement.

 

[F-Spot]

I can confirm that you can shift to 2H in Baja mode (FE owner). Traction control is disabled, and shift points increase to 5000 rpm, may be some changes in steering performance also.

I tried this today and sure enough, it does work. Can't say I like it for driving around town, as it does rev too high for my liking around town. It sounded like I was trying to race at every stop light, yet only slugging forward lol. I'll definitely reserve baja mode for offroading in the desert.

 

[JohnnyBronco]

That’s too many words at once. Can you summarize for me? Thanks ahead of time!

In nearly ALL 4wd vehicles including off road farm tractors, the front axle is designed to rotate the wheels slightly faster than the rear. This is so that the front pulls the back instead of being pushed, which can cause steering and control issues.

Now for the fewer words part..

Since in full time 4wd mode the front tires are turning faster than rear, all hell can break loose on dry pavement (,maybe not all hell but certainly more wear)

 

[AZSky]

So the Bronco is a 2WD on a normal pavement unless you have 4A.
Does 4A engage in rain (aquaplaning) ?

My Volvo has AWD, is this comparable to engaged Bronco 4A?

Volvo: To achieve the best traction, power is automatically directed to the wheels that have the best grip. The system continuously calculates the need for torque to the rear wheels, and can immediately redistribute up to half of the engine's torque to the rear wheels.

All-wheel drive also has a stabilizing effect at higher speeds. In normal driving conditions, most of the engine's power is directed to the front wheels. When the vehicle is stationary, all-wheel drive is always activated in preparation for maximum traction during acceleration.

 

[TheWoo]

So the Bronco is a 2WD on a normal pavement unless you have 4A.
Does 4A engage in rain (aquaplaning) ?

My Volvo has AWD, is this comparable to engaged Bronco 4A?

Volvo: To achieve the best traction, power is automatically directed to the wheels that have the best grip. The system continuously calculates the need for torque to the rear wheels, and can immediately redistribute up to half of the engine's torque to the rear wheels.

All-wheel drive also has a stabilizing effect at higher speeds. In normal driving conditions, most of the engine's power is directed to the front wheels. When the vehicle is stationary, all-wheel drive is always activated in preparation for maximum traction during acceleration.

4A is not exactly like AWD in most modern cars - but for purposes of driving, you can think of it similarly. Power is going to the rear axle in 4A most of the time, but will be delivered to the front axle when slippage happens.

 

[da_jokker]

So the Bronco is a 2WD on a normal pavement unless you have 4A.
Does 4A engage in rain (aquaplaning) ?

My Volvo has AWD, is this comparable to engaged Bronco 4A?

Volvo: To achieve the best traction, power is automatically directed to the wheels that have the best grip. The system continuously calculates the need for torque to the rear wheels, and can immediately redistribute up to half of the engine's torque to the rear wheels.

All-wheel drive also has a stabilizing effect at higher speeds. In normal driving conditions, most of the engine's power is directed to the front wheels. When the vehicle is stationary, all-wheel drive is always activated in preparation for maximum traction during acceleration.

And remember the 4A is the transfer case, not the differentials. So it transfer case clutches getting engaged and send power to the front axle, but the control which wheel on each axle is the power, traction control has to do that because it uses braking.

I've never had an AWD, but I'm assuming it's similar in that they are literally NOT able to control power directly to each of the four wheels (aka lockers vs open diffs) but instead use TC to to effectively use the brakes as a "locker"

 

[da_jokker]

Now with all that said, I know Jeep has at least 1 transfer case that uses clutch plates to allow slippage between the front and rear axles. As a result, you can put your vehicle in four-wheel drive "full time"

And I used to do just that, when it was raining hard. It really helped stabilize my XJ. Ironically over the weekend I was driving my Wrangler it only has part-time while it was pouring outside... And I really wanted to put it in four-wheel drive but was a big concerned due to this very thread.

So I'm glad that my Bronco is going to have 4a at least, And if I were to get a newer Jeep instead, I would get their version of 4A as an option.

 

[privateer35]

Put simply, NO you should not use 4H/4L on any surface that does not allow for good tire slippage. Do not confuse this with lockers, we are talking about the transfer case and it locking the front and rear drive shaft together.

Believe it or not, but going down the road your front axle and your rear axle do not spin at the same exact rate. Especially when you're turning. So locking the front axle to the back axle, which is required both a turn of the exact same speed, isn't really possible without slippage and puts extra tension on the drive train.


4A is an entirely different topic. When you place a Bronco into 4A, it is not going in to four wheel drive. It stays in two wheel drive until the computer senses wheel slippage between the front and the back and it automatically engages the transfer case clutch to distribute power evenly between the front and the back. So it is okay to run in 4A since you'll never actually be in four wheel drive unless you're slipping.

From my understanding, Slippery mode shifts into 4A. Would that mode be ok to drive on the highway when there is light snow and maybe some ice? Is it appropriate to run that mode around Highway speeds?

 

[da_jokker]

From my understanding, Slippery mode shifts into 4A. Would that mode be ok to drive on the highway when there is light snow and maybe some ice? Is it appropriate to run that mode around Highway speeds?

Yes... And that is exactly what it's for. You don't use 4A When you're off-roading. 4A is for those surfaces that normally provide good traction But for some reason maybe a bit slippery....eg it's pouring down rain, or there's light snow patches.


And FYI, sports mode switches to 4A.

 

[Drex]

I can confirm that you can shift to 2H in Baja mode (FE owner). Traction control is disabled, and shift points increase to 5000 rpm, may be some changes in steering performance also.

It would be inconceivable to me that Ford would also not be tweaking the stability control and the criteria for air bag deployment in some way as well. It may be compromising some safety features that normally are available for street driving. YMMV

 

[Dragline]

It would be inconceivable to me that Ford would also not be tweaking the stability control and the criteria for air bag deployment in some way as well. It may be compromising some safety features that normally are available for street driving. YMMV

Yeah, it's not really practical for street driving any distance anyway. Fun for a few miles but way too aggressive for normal driving.

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