Noticed this morning when reversing a (what can only be descibed as) low-frquency, dull thud-type sound. Only seems to occur in a 'phased' way i.e. per revolution, so am wondering if a cv joint is on the way out or, hopefully not, worse? Does not happen when moving forwards.

Any pointers before I call the garage?

Thanks

We had something like this on one of our cars. It turned out to be a snapped belt in a tyre. Lift each corner in turn and spin the wheel, make sure its round and doesn't have any bulges/flat spots. You can also check the bearings by trying to wiggle the wheel from side to side and top to bottom and see if there's any play.

We had something like this on one of our cars. It turned out to be a snapped belt in a tyre. Lift each corner in turn and spin the wheel, make sure its round and doesn't have any bulges/flat spots. You can also check the bearings by trying to wiggle the wheel from side to side and top to bottom and see if there's any play.

Thanks for the pointer. Was there any visible damage to the tyre?

Thanks

It was backlit and I was looking down from above the tyre and there was a clear dent in the face of the tread when I span the wheel. There was nothing visible when it was stood on it normally.