Discover the Ultimate Off-Road Hack: Should You Leave Your Truck in 4-Wheel Drive?
Engaging 4WD when surface traction is limited, such as in snowy, sandy, or icy conditions, can be beneficial as it reduces the likelihood of traction loss. By parking in 4-wheel drive mode on slippery surfaces, the vehicle remains stationary by utilizing the drive-train to support the parking brake. Parking your vehicle in 4-wheel drive mode overnight poses minimal risk of mechanical damage.
When operating a 4WD, following the manufacturer’s guidelines outlined in the owner’s manual is important to prevent unnecessary damage. Unintentional misuse or abuse can lead to costly repairs. With that being said, does extended periods of driving or leaving your vehicle in 4H mode, especially overnight pose risks to your 4WD system if not done correctly?
Understanding the proper operation of your 4WD involves delving deeper into its intricacies. Get to know your vehicle better, in other words. There are certain drive-train configuration differences among 4WD vehicles, and it is essential to recognize that not all 4×4 systems are identical.
What are the ramifications of engaging 4WD when it is unnecessary? What about parking in 4WD for extended periods? let’s find out.
NB: When parked on a downhill slope, it’s best to park in reverse gear. Conversely, if you’re parked facing an uphill slope, leave the vehicle in 1st gear.
Remember to always choose the opposite gear of the direction your vehicle is facing. This precaution is important because parking brakes can potentially fail or lose tension over time, particularly when parked on inclines or declines for extended periods.
Use The Transmission To Assist The Park-brake
The transmission and transfer case would essentially keep the vehicle firmly locked in place and safe from rolling down a driveway, possibly running into something or someone causing major damage to your vehicle and somebody else’s property.
When the vehicle is parked in 4WD, the drive-train will be “locked” in gear, 1st or reverse gear. There is also less wear and tear on your parking brake.
Is It OK to Drive In 4-Wheel Drive All The Time?
So to get the correct answer for your vehicle application, we need to essentially understand the 2 types of 4x4s.
- A full-time 4WD which is essentially a permanent 4-wheel drive
- A part-time 4-wheel drive. Non-permanent 4×4
So what is the difference and how does it affect the operation of the vehicle?
Unless traction is bad such as driving on low traction surfaces or in heavy rain, It is not advised to drive in 4WD mode for extended periods with a non-permanent 4×4 as this will result in “axle binding”, also known as ”drive-line binding” or “drive-line wind up”.
Extended driving in 4H, with a part-time 4WD truck, on a high traction surface like pavement, will result in drive-train components like u-joints, axle, transfer gears, bearings, and drive-shafts getting damaged and eventually failing.
Good read: Exploring the Power of 4WD
Permanent 4-Wheel Drive
Permanent 4-wheel drive means the vehicle cannot be removed or taken out of 4×4 (4H)mode at all. This means the vehicle is always in 4WD mode and there is no risk of operating and driving it on ANY particular surface in this mode.
Permanent 4WD makes use of a drive-train component (eg. viscous coupling) that allows the front and rear drive shafts to operate independently without causing any drive-line wind-up.
NB: if your 4WD can lock its center differential, always ensure that it is disengaged before you head back onto the tarmac or any hi-traction surface.
What Is Transmission Wind-Up?
Transmission wind-up occurs when a part-time 4WD vehicle is operated on a non-slippery surface like tarmac or pavement which does not allow the left and right side wheels on the axles to turn at different speeds while taking a bend.
- When cornering in 4WD, the difference in rotational speeds between the two inner wheels and 2 outer wheels causes the axle drive-train to wind up.
- This can cause major damage to tires and other drive-train components.
- The high torque generated inside the transfer box and other drive-train components is susceptible to major damage.
Example: If you are turning left the two wheels on the left side of the axles are turning slower than the two on the right side because the circumference is smaller. If the vehicle is in 4WD mode on a high traction surface then drive-train wind-up occurs because the axles want to turn at the same speed and that stress which it generates on the drive-train is what causes the axle-binding.
Transmission wind-up can be identified by tight gear shifting, grinding, transmission stuck in a gear, difficulty turning, and wheel hop, combined with increased fuel consumption.
These are some of the immediate tell-tale signs you have transmission wind-up as a result of driving in 4WD on a non-slippery surface. More about this later.
So Why Are All 4WDs Not Built With Permanent 4WD?
Well, there is a trade-off to having the capability of being able to operate and drive on any surface with no risk of damage to tires and drive-train. The trade-off for permanent 4WD is the following:
- Slightly Higher fuel consumption than 2WD vehicles
- More operational components (more serviceable parts)
- Higher maintenance costs
- High repair costs
- More expensive purchase price (more components and technology built-in)
- Heavier vehicle curb weight
- Usually has a lower Towing Capacity than a 4×2 version of the same make and model
Below are some examples of vehicles with permanent 4WD and AWD
- Subaru Forrester (AWD)
- Jeep Wrangler (AWD)
- Jeep Grand Cherokee (AWD)
- Toyota 4Runner (AWD)
- Jeep Wrangler (4WD)
- Land Rover Defender (4WD)
- Land Cruisers (4WD)
- Ford Ranger (4WD)
- Toyota Tacoma (4WD)
Difference Between 4WD and AWD Facts
| Permanent 4WD | AWD SEDAN |
|---|---|
| Works well on-road | Performs excellent on-road |
| Very capable off-road | No low-range gearing – limited off-road |
| 25% torque distributed to each wheel | No lockable center diff |
| Torque distribution: 50/50 | Torque distribution varies: 50/50, 60/40, 80/20 |
| Up to 3 lockers | No diff lockers |
Some vehicles equipped with permanent 4WD or AWD systems offer a balanced torque distribution, with roughly 25% of torque being sent to each wheel. However, manufacturers have different preferences when it comes to torque split. While certain manufacturers opt for a 50/50 torque distribution, others prefer a 60/40 split.
On the other hand, some manufacturers go for a sportier feel by implementing an 80/20 torque split, with the higher percentage of torque always being distributed to the rear axle.
The significant difference between the two types is that a 4-wheel drive has a low-range transfer case whereas an AWD does not have any low-range capabilities, transfer case, or diff lockers.
Can you leave your truck in 4X4 all the time?
Yes, but only if surface traction is low such as sand, mud, snow, ice, or grass. If traction is good remain in 2H or 4A if surface traction is mixed.
Should I leave my truck in auto 4WD?
Auto 4WD (4A) allows you to safely leave your truck in 4WD if driving conditions are mixed between low and high traction. There is no risk in leaving it in Auto 4WD.
Is it OK to drive in 4WD on the highway?
Yes, only if the road surface traction is low such as snow, heavy rain, or icy road conditions. If traction is good remain in 2H or 4A if surface traction is mixed.
Final Thoughts
Before engaging in 4-wheel drive, it is crucial to become acquainted with the owners and operations manual for your particular vehicle. Parking a vehicle in 4-wheel drive or 4H is generally safe, regardless of whether it is permanent or non-permanent 4WD.
However, it is important to note that non-permanent 4-wheel drives should not be driven on surfaces with ample traction, such as bitumen/tarmac, cement, and pavements. Optimal surfaces for non-permanent 4-wheel drives include grass, asphalt, sand, mud, and snow.
