
There is a rotary switch on each of the front wheel axles, located inside the protruding hub on the front axle. This rotary switch is the 4WD/2WD selector. To engage four-wheel drive, turn the rotary switches on both front wheels to the ON position. For two-wheel drive, set them to OFF. Four-wheel drive distributes the engine's power to all four wheels, significantly improving the vehicle's handling and off-road capability. Currently, four-wheel drive systems are generally categorized as follows: Full-time four-wheel drive means the vehicle remains in four-wheel drive mode throughout the entire driving process. This mode offers excellent off-road and handling performance, though no domestic pickup trucks currently feature this system. Full-time all-wheel-drive vehicles provide a more stable and safer driving foundation compared to two-wheel-drive models, especially in extreme road conditions or during aggressive driving, with higher active safety. Part-time four-wheel drive is a manually selectable mode, where the driver can switch between two-wheel drive and four-wheel drive by engaging or disengaging the transfer case. This is the more common drive mode in domestic pickup trucks, offering a balance between power, off-road capability, and fuel efficiency. The slight drawback is that the driver must assess road conditions independently and manually switch drive modes while stationary.

When off-roading in my pickup truck, I've found that using the 4WD system requires finesse. The 2WD mode is for regular roads, saving both fuel and vehicle wear. When encountering rainy dirt roads or snow-covered surfaces, promptly switch to high-range 4WD, keeping speed below 80 km/h during gear changes. For steep slopes or rough terrain, you'll need to stop, shift to neutral, and depress the clutch to engage low-range 4WD - this provides maximum torque for the toughest situations. Remember to switch back to high-range 4WD immediately after clearing obstacles; don't run low-range on flat ground for extended periods. After each off-road trip, it's best to check the transfer case oil level and clean mud from the driveshaft - this significantly extends the 4WD system's durability.

Off-road veterans know that timing is everything when shifting a pickup's 4WD system. Use 2H (two-wheel drive) on dry asphalt roads, then switch to 4H (high-range four-wheel drive) when you feel tire slippage. For serious mud or steep climbs, come to a complete stop before engaging 4L (low-range four-wheel drive) - keep speeds below 40 km/h after shifting. Maintain steady speed when crossing riverbeds; sudden acceleration risks water intake. I always preemptively switch to 4H before snowfall for slip-free starts. Never neglect 4WD maintenance - shift gears at least twice monthly to prevent rust seizure.

Mastering the use of 4WD modes is essential for pickup truck drivers. For daily commuting, 2H mode is the most fuel-efficient option. Switch to 4H when encountering muddy or sandy terrain, remembering to shift gears while moving slowly or stopped. Engage 4L low-range mode for maximum traction when climbing steep slopes or towing heavy loads. However, never use 4WD on paved roads, especially during turns, as it can damage the differential by causing tire scrubbing. While two-wheel drive suffices for most situations, reduce speed when cornering in rainy conditions. Always test steering responsiveness after switching 4WD modes to ensure proper engagement. Regular inspection of front and rear axle fluid levels is crucial.

The four-wheel drive system of a pickup truck should be used according to different scenarios. On regular roads, maintaining two-wheel drive is the most cost-effective, offering higher fuel efficiency. When preparing to enter mountain roads or encountering wet conditions, switch to high-range four-wheel drive in advance. If the vehicle gets stuck in mud, you must come to a complete stop before switching to low-range four-wheel drive to escape, as this will amplify the torque by two to three times. Special note: When switching back to two-wheel drive, ensure the front wheels are fully disengaged. I make it a habit to check the transfer case for oil leaks after each refueling, and for vehicles that primarily use two-wheel drive, perform a four-wheel drive test quarterly. The depth of the tire tread also affects the effectiveness of four-wheel drive—if the tread is worn, avoid forcing your way through muddy terrain.