Volvo Trucks first with automatic all-wheel drive

“Many drivers connect front-wheel drive or differential lock in good time before a difficult section of terrain, in order to avoid getting stuck. Volvo Automatic Traction Control engages the front wheel drive when in motion, and only for the short time that it is really needed,” says Jonas Odermalm, Construction Segment Manager at Volvo Trucks.

Volvo Automatic Traction Control, which has now become standard in the Volvo FMX with driven front axle, is already used by Volvo Construction Equipment in their articulated haulers. The solution consists of software connected to the wheel speed sensors which detect and control wheel drive. When a rear wheel starts to slip, the power moves automatically to the front wheels without the truck losing torque or speed. A dog clutch activates the front-wheel drive in just half a second. The clutch is lighter and has fewer moving parts than a traditional solution with permanent all-wheel drive. If the driver encounters particularly rough ground, then it is possible to manually lock the other differentials at both front and rear.

The drive on the front axle prevents standstills on slippery surfaces. At the same time, the function is often only required for a very small part of the total driving time. With Automatic Traction Control, the front tires’ grip is concentrated on the steering right up until any critical situation. Thus, the driver can take advantage of the better manoeuvrability for as long as possible. The driver also avoids extra fuel consumption and wear on the driveline and tires, that the constant engagement of front-wheel drive normally results in. Automatic Traction Control ensures that the optimal drive combination is always enabled and removes the decision from the driver.