Drive Axle
A shaft that transmits rotational torque from the transmission or differential to the driven wheels.
A drive axle is a heavy-duty steel shaft that transfers rotational torque from the transmission or differential to the wheels that drive the vehicle. Depending on the drivetrain layout, a vehicle can have front drive axles (front-wheel drive), rear drive axles (rear-wheel drive), or both (all-wheel and four-wheel drive).
In independent suspension systems, drive axles are fitted with CV joints on both ends, allowing the axle to flex as the wheels move up and down over bumps and pivot during steering. In solid axle designs, the axle shaft is housed inside a rigid steel tube, splined directly into the differential gears.
Drive axles are subjected to massive torque loads and road stress. Symptoms of a failing axle include vibration under acceleration, clicking noises during turns (on CV axles), or gear oil leaks from the axle seals. Replacing a damaged drive axle is critical to prevent complete loss of drive power and wheel lock-up.