Most steering rack problems on Audis develop slowly, so it is best to check for early warning signs and do a repair before the job becomes a lot bigger.
Knocking or Clunking Over Bumps
Worn steering rack mounts or loose tie rod ends can cause a knocking sound to emanate from the front of the car when going over speed bumps or driving down uneven sections of road. The knocking sound can be a hollow sounding knock that can be felt through the floor of the car as well as heard.
Steering Wheel Feels Loose or Vague
A worn steering rack can cause the steering to become loose or vague. This is more common on older Audis and can develop slowly over time. If you compare the steering of your car to another similar model you may notice that the steering of your car is not as precise.
Pulling to One Side
If the steering rack has become worn unevenly or has developed some form of internal damage, this can cause the car to pull to one side. This can be caused by other things as well though, such as wheel alignment problems, and a good mechanic would check both of these for you. However, if after having your wheels realigned, the car still pulls to one side then the problem is likely to be with the steering rack. See also Audi Steering Racks.
Fluid on the Garage Floor
The Hydraulic Audi Steering Rack relies on seals within the housing to retain the steering fluid. These seals are designed to be durable, however as time passes they can harden and eventually crack. When a seal cracks fluid will leak out of the housing. Typically the fluid will leak out slowly at first and form a thin patch on the garage floor or under the car. It is crucial to address this issue as soon as possible, because as the fluid level drops, the strain on the steering pump increases significantly, potentially causing serious damage.
Heavy Steering at Low Speeds
Heavy steering when parking or low speed driving could be due to a faulty steering rack or low hydraulic fluid. If your car is equipped with an electric steering rack on later models of Audi then it can suffer from heavy steering and show a warning light on the dashboard as well.
Catch any of these symptoms early and you can save yourself a world of pain with a simple repair to rectify the problem.