Ford F-250: 4WD General Information/Specs

If you want to go off-roading, four-wheeling, or just feel safer in bad weather, the Ford Super Duty 4WD option might be just what you are looking for. Not sure about 4WD versus 2WD? Read on and learn everything there is to know about 4WD versus 2WD on the Ford Super Duty.

By Jeffrey Smith - November 24, 2014
Contributors: Jeff Smith

This article applies to the Ford F-250, F-350 Super Duty (2006-2014).

From the outside, a four wheel drive (4WD) F-250 is indistinguishable from the two wheel drive (2WD) version. Mechanically, however, they differ greatly. The 2WD pickup has all the power in the rear wheels. The engine turns the drive shaft which turns the rear axle. Only rear wheels drive the truck; the front wheels spin freely and receive no power.

In the 4WD version, the front axle can be called into service on the fly. In bad weather or poor driving conditions, the operator can flip a lever inside the cab and the front axle connects to its own drive shaft, which connects to the engine. The front axle then receives power from the engine just like the rear wheels. Locking the axles will cause your turning radius to shrink, unfortunately. Also, because engine power is now dispersed to two different axles, the gas mileage will decrease a little. All four tires now carry all of the weight, which helps traction a great deal; this is the benefit of having a 4WD vehicle in snow, mud, rain, and in generally poor driving conditions. To make all of this happen, the 4WD vehicle has many specialized parts or components.

Common Questions

Why do I want 4WD?

People who frequently drive off-road will want 4WD—especially if they frequently travel through slick or loose terrain. Having two more working tires will go a long way towards getting a stuck truck un-stuck. In general, having the option of 4X4 drive is useful in conditions where traction is an issue. Also, the extra low gearing and additional torque make 4WD the better choice for towing. However, if the truck spends its life mostly on pavement, 4WD is less necessary. Also, opting for a 4x4 drivetrain will reduce the payload considerably.

How much does 4WD cost?

Upgrading to 4WD on a brand new, 2015 XL F-250 will cost you an additional $2,800 dollars.

What are the driving differences in 4WD?

The biggest difference you'll notice is the smaller turning radius due to the axles being locked in. You'll also notice that it will feel like you have less power; this is due to some of the power being lost in the front drive train as it's sent to the front axles.

When should I not use 4WD?

Do not use 4WD on dry pavement. When the conditions do not warrant 4WD, do not use it. Doing so can cause the inner and outer joints in the CV to bind up and wear out prematurely. You should periodically check that it is working properly by running in it for a short period of time, but you should do this on wet grass or mud.

Does 4WD eat up my gas mileage?

The added weight of a 4WD system will impact fuel economy, but considering the overall weight of the vehicle, the difference will be minimal. The additional safety it provides in poor road conditions should give peace of mind that offsets any concern for poor gas mileage.

Common Issues

Automatic Hub Failures

Many Ford owners complain of the automatic feature of their hubs no longer working. They have to manually put their hubs into lock and then switch into 4WD mode. Inside the hub, the parts are made of plastic which wear out quickly. Another common issue is the wearing out of vacuum lines. Replacing the vacuum lines and system can be costly, so a common resolution is to replace the OEM auto hubs with aftermarket manual hubs and capping off the vacuum hoses.

(Related Article: Why Can't I Get Into/Out of 4WD? - Ford-Trucks.com)

4WD Components

Front Drive Axle (CV Axle)

This is your front CV axle. Depending upon the model year of your Super Duty, it will likely freely spin with the front tires in 2WD. In 4WD, the front drive shaft will connect with this axle and will start spinning the tires under engine power. In 4WD, the turning radius is greatly diminished, and attempting to turn too tightly will put binding pressure on the inner and outer joints. Over time, this will cause those components to wear out. If the dust covers get torn, they will need to be replaced in short order, and the joints will likely need replacing at the same time.

Figure 1. Front axle; spins freely in 2WD or under engine power in 4WD.

Wheel Hubs (Front Axle Actuators)

The hubs mechanically connect the wheels to the front CV. When the hubs are unlocked, the wheels spin freely, not connected to the powered shaft. When the hubs are locked, the wheels and the CV are powered and spinning by the engine. The hubs do not affect or change the differential at all. When in the lock position, the hubs are considered "manual." If you put the hubs in the "auto" position, this works in conjunction with "Electronic shift on the fly" (ESOF) vehicles. There is a switch in the dash that actuates a vacuum system that automatically locks the hubs when you shift into 4WD.

  • Figure 2. 4WD locking hub. The front CV attaches to this gear in your wheel when 4WD is engaged.
  • Figure 3. 4WD Actuator. This component physically locks your front CV to the wheel hub (fig 2). They can be engaged by twisting the lock on the face of the wheel, or by engaging 4WD mode from the cabin.

Transfer Case

The transfer case is mounted onto the rear end of the transmission. There are two yolks on the transfer case. The rear yolk holds the rear drive shaft which is always engaged as it controls the rear axle in 2WD. When the operator switches into 4WD, the transfer case control module causes the transfer case to engage the front wheel drive shaft, which in turn, engages the front, or CV axle.

Figure 4. Transfer case. This controls the front and rear drive shafts from the transmission.

2WD/4WD Selector

The switch on the dash controls the hubs and the transfer case for ESOF Super Duty trucks. Engaging into 4H can be done while driving out of 2WD. The vehicle must be stopped or moving at less than 3mph while moving from 4H to 4L. The transmission must also be in neutral while shifting from 4H to 4L.

Figure 5. 4WD selector switch. Engages the vacuum system to lock the hubs, transfer case control module to engage front drive shaft.

Scheduled Maintenance

Follow the regular maintenance schedule for your Ford truck. At every oil change, the 4WD components should be inspected, and joints lubricated. Visually inspect the dust boots for tears or holes. At 150,000 miles, the axle and transfer case fluids should be replaced.

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