Over time, the rubber steering gaiters can split or get punctured from flying objects coming off the road. The gaiter protects the cup and ball joint on the steering rack and if it is damaged should be replaced straight away to prevent permanent damage to the rack itself.
This job is a doddle as long as you can get the track rod end apart. Jack up the side of the car you are working on and remove the front wheel. Locate the track rod end which is the joint that attaches the steering rack to the wheel. Undo the castellated nut from the top of the track rod so that it is flush with the top of the thread. Now, using as a piece of wood resting on top of the nut, strike it hard with a hammer. After a few blows, the ball joint should separate and you are free to remove the nut and the track rod will fall away from the wheel.
Next job is to remove the track rod from the end of the steering rack. It is held in place by a locking nut which can be released by using two spanners; one on the fattened section of the track rod and the other on the nut itself. Before attempting to release it, I suggest you mark its location carefully using some correction fluid as it must go back in the same place. This nut is usually quite tight so be prepared for a good heave. This is usually the point where the nut suddenly slackens and my hand go flying into the wheel arch, causing much pain.
With the nut released, the track rod can be removed by unscrewing anti-clockwise. To be extra careful, count the number of turns you take to get it off. The locking nut needs to be removed as well. With all that out of the way, you can now get to the gaiter itself. It is held in place at each end by metal clips which can be removed and may be required for the new one. The gaiter will slide off the steering rack and the new one put in its place. Take the opportunity to grease up the exposed part of the rack before fitting the new gaiter. This should be tied in place with the clips supplied or use the original ones. Now the track rod end can be re-fitted. First screw the locking nut on the thread followed by the track rod end itself. Count the same number of turns to ensure it is fitted in the correct place. Now tighten the locking nut using two spanners, making sure that the track rod end stays pointing upwards at all times. The ball joint can be gently tapped back in place and the castellated nut re-fitted. The entire job should take no longer than thirty minutes.