You can check the rings very easily using a torch! The failed ones are *likely* (95% probability) to be the fronts.
Under the front bumper, look at the inside of the wheel and look for the toothed ring as seen here (not a Clio):
Cracked rings are a pretty straightforward fix for any DIY mechanic. I'd allow a few hours for a newbie.
IIRC:
- Jack car up
- Wheel off
- Hub nut loosen
- Free drive shaft (Careful that the d/s doesn't come out of the gearbox on the passenger side!)
- Remove the 2 ball-joint nuts under the wishbone
- Hub nut off
- Slide shaft out of hub
- Remove old ring (if it's cracked, this'll be easy!)
- Carefully fit new ring (£10 ebay, I seem to recall that OE ones are £25 from Renault for the 172) - Interference fit so need bashing on evenly around the shaft.
- Clean-up and [reverse process]