This article discusses if and when you can switch from 4WD to 2WD while driving. Before switching your vehicle from 4H to 2H, it is important to understand and be familiar with your vehicle’s 4WD system. Over the years there have been major technological advancements in 4WD systems that are designed to make the operation of vehicles simpler.
When driving a modern 4WD you can safely switch from 4WD to 2WD (4H to 2H) while driving provided your speed is below 100kph/60mph. Modern electronic 4WD features make this safe to do. Older, more traditional 4WDs require the vehicle to be stopped before switching back to 2H.
Irrespective of what kind of 4WD you own, it’s always recommended to refer to your owner’s manual for specific instructions on how to engage or disengage from 4H to 2H and how to properly switch from 4WD to 2WD while driving.
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Can You Switch From 4WD To 2WD While Driving? (4H To 2H)
Thankfully, with a more modern four-wheel drive system, you can safely toggle the drive mode between 2H to 4H and back to 2H while driving. Always ensure you are driving below 60mph(100km) or less before switching back to two-wheel drive.
4WD to 2WD (4H to 2H) mode is usually selected before we jump back on the tarmac or any dry pavement after driving offroad in 4H. In severe weather and heavy rain, you can engage 4H on the wet pavement safely since this will provide much better traction when four-wheel-drive mode is engaged.
Switching From 2H To 4H
Most modern 4WDs allow you to safely switch from 2H to 4H (4WD) while driving at speeds below 100kph/60mph. A part-time 4WD is normally driven in 2-wheel drive mode. Usually, the front wheels just roll while the rear propels the vehicle forward, just like a rear-wheel drive car.
When switching from 2-wheel drive to 4-wheel drive on a traditional 4WD, remember the following procedure. Use the following steps below.
Procedure for Switching from 2WD to 4WD on a Traditional 4WD:
|1||Reduce speed to under 100kph/60mph.|
|2||Lift your foot off the gas pedal.|
|4||Wait for the 4H light to stop flashing on the dashboard.|
|5||Continue driving in 4H.|
Always ensure you are driving on low traction slippery roads or uneven terrain such as snow, muddy surfaces, sandy tracks, grass, or gravel before engaging 4H. 4H means you are in 4×4 mode but you are still using the high-range gears. The front differential located on the front axle is rotating the front wheels which are pulling while the rear wheels are still pushing forward.
Switching From 4H To 4Lo
Alternatively, when switching from 4H to 4-Lo (low-range), it is recommended to slow down to 5mph without the gas pedal depressed and the transmission in the (N) Neutral position before engaging the lower gears. Older 4WDs without automatic locking hubs require you to stop the vehicle completely, exit the vehicle, and manually engage the front hubs. Once the process is complete you can then engage 4H and 4L from inside the cabin. When 4Lo is engaged you can expect to feel a slight thump as the low-range gears engage, which is normal. Do not be alarmed it just means you have successfully engaged the set of low-range gears.
Procedure for Switching from 4H to 4-Lo on a Traditional 4WD:
|1||Slow down to under 8kph/5mph or stop completely|
|2||Remove foot from gas pedal|
|3||Engage Neutral gear|
|5||Engage 1st or 2nd gear|
|6||Slowly depress the gas pedal|
Please note that this procedure appears to be related to operating a vehicle with specific gear settings. It is important to follow the instructions provided by the vehicle manufacturer for safe and proper operation.
Switching From 4Lo To 4H
In most modern and traditional 4WDs it is safe to switch from 4H to 4Lo while driving slowly. Always make sure you are still on a slippery low traction surface before disengaging 4Lo. Changing from 4Lo to 4H means you are engaging from smaller gears to larger gears in the transfer case and therefore minimal risk of damaging the teeth and spline inside the TC (Transfer Case). When you switch from 4Lo back to 4H your front driveshaft is still engaged, however, the vehicle is changing between the low-range gears and high-range gears. Both the front drive shaft and rear drive shaft are engaged to work as a single unit.
Procedure for Switching from 4Lo to 4H on a Traditional 4WD:
|1||Remove your foot from the gas (Accelerator).|
|3||Engage Neutral gear in the transmission.|
|4||Switch to 4H.|
|5||Engage the appropriate gear according to your speed (2nd/3rd).|
Switching From 4H To 2H
Always make sure you are driving on or slowly approaching a high traction surface before you engage 2H and that you are driving in a straight line. This will avoid any potential drivetrain binding or damage to drivetrain components.
- Reduce speed to under 100kph/60mph
- Depress clutch
- Engage 2H
- Engage appropriate gear according to your speed (2nd/3rd)
- Release the clutch and continue driving safely.
Is It OK To Drive In Auto 4WD (4A) On The Highway?
Yes, it is absolutely safe to drive in 4A on the highway. Auto 4WD is designed to be used in conditions where surface traction is mixed. Perhaps on a rainy day or when there are patches of snow or ice on the road while other sections are clear, engaging (4A) Auto 4WD will be the best option.
Auto 4WD will only engage 4H when it detects that traction is low. The 4A system makes use of multiple wheel sensors and a very advanced traction control system that constantly monitors wheel traction to detect slippage. This is done in milliseconds without any additional input required by the driver. When traction is good the Auto 4WD system will revert back to 2H. You have the best of both worlds of fuel economy and maximum traction in the 4A setting. Read more about 4A here.
Can 4WD Be Turned Off?
Yes, 4WD can be turned off, but only if you are driving a part-time 4WD vehicle. In that instance, you can switch from 4H to 2H which disables 4WD. When you are driving a permanent 4WD you cannot turn off 4WD as it constantly sends torque to both front and rear axles.
A full-time or permanent 4WD system is designed to be driven on low and high-traction surfaces safely. On a traditional 4WD, there is a component that makes this possible called a viscous coupling that allows the front and rear driveshafts to rotate at dissimilar speeds while cornering.
On more modern 4WDs that is permanent four-wheel drive, that uses an electronically controlled on-demand two-speed electromechanical transfer case (EMTC). This technically means the vehicle is always in 4H but switches between 2H and 4H on the fly. Very similar to Auto 4H.
If you find yourself driving in 4H on a dry, paved road, it’s recommended to switch to 2H to reduce wear and tear on your vehicle’s drivetrain, improve fuel efficiency, and reduce the risk of tire damage or drivetrain binding.