OK to always leave in 4A?

Based on, among other things, threads here re: the grinding issue tied to the IWE, I drove in 4A for a few days. Like the OP, the mechanic at the Ford dealership I go to in Houston and my service adviser gave the same warning--don't drive in 4A all the time. They said something about it potentially causing overheating. With the IWE issue fixed (for now), I don't have a need for 4A unless I go into Rain Mode, so it's a non-issue. But it is just another frustration--on top of others, like hard shifting from 4th to 5th in Sport Mode--that don't breed confidence in Ford.

tmanker said:

Even if you can drive in 4A 100% of the time, why in the hell would you want to?

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Nearly all SUVs and trucks, and many cars come with AWD systems. That's what "4A" is... so if AWD sounds better than 4A for continuous use, please substitute. Ford just wanted a feature of "select ability", and "4A" goes with the other mode names better than "AWD".

"Why would you want to"? For the primary reason of AWD systems... to have better vehicle control in any and all normal driving conditions... especially unexpected conditions when "switching" to 4A is too late.

You can easily watch the Power Distribution when in 4A, and see that it rarely applies power to the front wheels during normal pavement driving... usually only on hard acceleration... but it's ready when needed.

Yes, you can lighten the steering feel, by using Comfort Steering while in 4A.

Speed limit in 4A is the same as 2H is the same as 4H.

Gas mileage... drove home 400 miles in 4A (due to IWE grinding in 2H) at 65-75mph and averaged 17mpg... same as 2H.

My original question stands. If you get a positive response from leaving in 4A full time, great. If road conditions warrant leaving in 4A for an extended period of time, why not use 4H? Also, you can't compare the Torsen differential to 95% of garbage AWD systems.

tmanker said:

My original question stands. If you get a positive response from leaving in 4A full time, great. If road conditions warrant leaving in 4A for an extended period of time, why not use 4H? Also, you can't compare the Torsen differential to 95% of garbage AWD systems.

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How do you define extended? I went up to the mountains yesterday and while the roads were plowed there was several sections of ice from when the snow was melting during the day and frozen back over as it cooled. 4A was perfect for these unpredictable conditions and it was like that for several miles.

Condition 1 - DIFFERENTIAL ACTION

When cornering, the outside wheel of the driven axle, initiated‑‑by the rolling engagement of the wheels to the road, must increase its RPM level relative to the differential housing. At the same time the inside wheel must decrease its RPM level in the same proportion (e.g. outside wheel +4 RPM, inside wheel - 4 RPM). The worm attached to the outside axle will increase its RPM level relative to the differential housing, thus the worm will turn its mating worm wheel. The worm attached to the inside axle will decrease its RPM level relative to the differential housing, in the same proportion as the outside wheel is increasing its RPM level and will also rotate its mating worm wheel. The two worm wheels in the "TORSEN" Differential are in mesh with each other through the spur gears on a one-to-one relationship and act as balancing gears to maintain perfect differentiation while maintaining torque to both wheels.


https://www.flashoffroad.com/features/Torsen/Work/torsen_works.htm

tmanker said:

My original question stands. If you get a positive response from leaving in 4A full time, great. If road conditions warrant leaving in 4A for an extended period of time, why not use 4H? Also, you can't compare the Torsen differential to 95% of garbage AWD systems.

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I'd only run 4Hi if the roads were completely snow covered. 4A is best for when the roads have patches of bare pavement and snow covered pavement.

I too leave mine in 4A in wet weather or surfaces with less traction. Hasn't caused me any problems

I put mine in 4a at the start of winter and leave it there.

borzraptor said:

I too leave mine in 4A in wet weather or surfaces with less traction. Hasn't caused me any problems

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And it won't!...can't believe this thread has gone so far...Someone asked about "extended time" and what that would be. It's so simple!

If conditions warrant 4A then use it!...if it snows everyday for a week and your daily commute round trip is 80 miles, then yes use it every snowy day, it's made for that.
The flip side is also simple...if there are no traction issues, why would you use 4A and just add additional wear to some of the parts?

Loufish said:

And it won't!...can't believe this thread has gone so far...Someone asked about "extended time" and what that would be. It's so simple!

If conditions warrant 4A then use it!...if it snows everyday for a week and your daily commute round trip is 80 miles, then yes use it every snowy day, it's made for that.
The flip side is also simple...if there are no traction issues, why would you use 4A and just add additional wear to some of the parts?

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Because people can't be bothered to read the manual, or trust the people who built the truck. Same guys who run the on-road modes off pavement, or swear Baja 2H is quickest at the drag.