Rack and pinion steering relies on a gear set to convert the turning movement of the steering wheel into the motion required to turn the wheels. When this system is combined with power steering, the configuration changes slightly to include a cylinder with a piston in the middle. Check out this guide for a detailed explanation of how your a car's steering system works.
The three top reasons for a steering rack repair or replacement are: cracked rubber lines and hoses, loose connections and failed seals between the steering column and rack and pinion.
Common signs of a problem include leaking power steering fluid, loose or inconsistent steering, vibration on the steering wheel, wheels not returning to the centre and instability on the motorway.
If your Renault has any of these symptoms and the damage is too severe to repair, you may need to book a steering rack replacement. It's best to contact a steering rack specialist for advice.