Hi Kate. IT's a "trackrod balljoint" that your dust covers have perished on.
they're easy to fix. You can't get the dust covers on their own, you need to change the whole trackrod end. But don't worry, they're very cheap and easy to do
Have a look at this guide here:
http://www.saxperience.com/forum/sho...d.php?t=132039
The photos are missing as it's an old guide, but the words still make sense! If you get stuck, give us a shout