CV joints and axles: the clicking noise on turns

if your car clicks or knocks when you turn at low speed, particularly on full lock in a parking lot, that is the classic sound of a worn CV joint.

what the axle does

the axle carries power from the transmission to the wheel. on front wheel drive and most all wheel drive vehicles it has to do that while the wheel steers and moves up and down, which is what the constant velocity joints at each end are for.

those joints are packed with grease and sealed inside a rubber boot. the joint itself is strong and lasts a long time. the boot is the weak point.

the failure sequence, which is always the same

1. the boot splits, from age, cold, or a stone. at this stage it is a cheap repair and often no symptom at all.
2. grease is flung out, and you may see it sprayed around the inside of the wheel. dirt and water get in.
3. the joint wears, because it is now running on grit rather than grease.
4. it clicks on turns. by now the joint is done and the axle gets replaced.

the whole thing takes months to years, and it starts with a torn rubber boot that costs very little to catch.

what to listen and look for

• clicking on tight turns, worse under power
• a vibration under acceleration that is not there when coasting
• a clunk when moving off or changing between drive and reverse
• dark grease around the inside of a front wheel, which is the early warning nobody looks for

why we mention the boot so much

because a torn boot found during a routine service is a small job, and the same axle six months later is not. it is on our inspection list for that reason, and it is one of the things you will see on a reconditioning list if we found it on a vehicle before it was listed.