Expensive tire sidewall cracks; slow leak

Maintenance/Repairs
211

Simple, AWD:

  • Torque Distribution:

AWD systems constantly monitor wheel speed and traction to determine the optimal torque distribution to each wheel.

  • Center Differential:

A center differential (or equivalent) allows the front and rear axles to rotate at different speeds, which is crucial for smooth cornering and preventing binding in AWD systems.

  • Slippage Detection:

Sensors detect when a wheel loses traction (e.g., on ice or snow) and redirect power to the wheels with better grip.

  • Full-time vs. Part-time:

Some systems, like Subaru’s, are full-time AWD, meaning they constantly distribute power to all four wheels. Part-time AWD systems may primarily operate in front-wheel drive or rear-wheel drive mode and only engage the other axle when needed.

  • Electronic Control:

Modern AWD systems often use electronic controls and clutches to manage torque distribution, allowing for quick and precise adjustments based on driving conditions and driver input.

Traditional Four Wheel Drive does not have a center differential.
Key Characteristics of Traditional 4WD:

  • Transfer Case:

A key component that allows the driver to select between two-wheel drive (typically rear-wheel drive for trucks) and four-wheel drive (4H for normal conditions, 4L for low-speed, high-torque situations).

  • High and Low Range Gearing:

The transfer case often offers a low range option, providing increased torque at lower speeds for better off-road performance.

  • Driver-Selectable Modes:

Drivers can typically choose when to engage 4WD, unlike some AWD systems which are always active.

  • Locking Differentials:

Some 4WD systems offer locking differentials, which force both wheels on an axle to turn at the same speed, providing maximum traction in challenging conditions like deep mud or snow.

  • Suitable for Off-Road:

4WD systems are designed for rough terrain, offering enhanced grip and control when navigating obstacles.

Using 4WD on dry pavement can cause drivetrain binding and potential damage, as the front and rear wheels need to rotate at different speeds during turns.

Try driving a 4X4 on pavement with 4WD engaged, you will soon learn the difference.

2 Likes