These items are notoriously short-lived.  Mine only lasted 4 years/10000 miles.

They reside under the steering box which has a typically English characteristic.  If  it’s not leaking oil it is empty!  Even the “dry” one on the idler side was disintegrating.
This is not synonymous with maintaining rubber bushes in good condition! 

Answer, replace bushes with Nolathane type.  These should be available from your suspension  shop, less than $50 for the pair, and are easier to replace than the standard type.
Part number is 41033.

The original bolt has to be removed from the old bushes, if yours are like mine, the  rubber has degenerated so much they will fall out!  Clean off all traces of rubber,  lube the pin with the supplied grease and simply push the two halves of the new  bushes into the drag link and refit the pin. 

The Nolathane is impervious to oil, has  less friction than the rubber, will give more positive and lighter steering.

One suggestion I have received re leaky steering boxes, thoroughly mix 90 or 140  grade gear oil with grease.  Make as this thick as possible whilst still being able  to actually get it into the ’box.  It will still provide lubrication whilst greatly retarding leakage.

Mike King