The task of the rear axle is to transfer drive to the road surface as efficiently and with as little drive loss as possible. Low frictional losses and well-matched fast rear axle ratios are the main factors that benefit fuel consumption.
Volvo's rear axles have been built to handle the rough stuff. They are made of sturdily dimensioned components to deal with the extreme loads and stresses to which a rear axle is subjected. There are variants that can transfer engine torque of up to 3100 Nm and can haul gross combination weights way in excess of 100 tonnes.
The rear axle range is wide - it encompasses solo and tandem axles, with single or hub reduction. All the rear axles have a differential lock. Tandem axles also have an inter axle differential lock.