🔩 CVD
Constant-Velocity Driveshaft — a driveshaft design that transfers power smoothly even through a wide range of suspension angles, common on 4WD vehicles.
What it actually does
A CVD — constant-velocity driveshaft — transmits drive to a steered wheel while keeping the speed even through the joint. A simple universal joint speeds up and slows down slightly through each rotation when it is at an angle, and at full steering lock that unevenness is something you can feel.
In practice
CVDs are a common upgrade on the front of 4WD cars, where steering angles are largest. The benefits are smoother steering, less vibration and less shock through the drivetrain. Standard dogbones remain perfectly adequate at the rear, where angles are small.
Worth knowing
CVDs have more small parts — pins, cross pins and grub screws — and they need periodic greasing. Check the pins are retained properly, because a pin working loose ends the run.