Driveline Clunk

It often comes from play in mounts, joints or the differential. It is more common on rear-wheel and four-wheel-drive cars. It may be louder when the drivetrain is cold. Mechanics look for play by rocking the drivetrain by hand with the car safely raised and the gearbox in neutral. Worn universal joints, loose propeller shaft bolts and backlash in the differential are typical causes, and an oil level check is a quick first step.

Play in the drivetrain lets parts move freely until they take up the load with a knock.

Check engine and gearbox mounts, propeller shaft joints and CV joints. A growing clunk should be inspected before parts fail.