Fixed joint set to chuck overboard (8)
I believe the answer is:
jettison
'chuck overboard' is the definition.
(I've seen this before)
'fixed joint set' is the wordplay.
'fixed' is an anagram indicator.
'joint'+'set'='jointset'
'jointset' is an anagram of 'JETTISON'.
'to' acts as a link.
(Other definitions for jettison that I've seen before include "Throw overboard or discard unwanted material" , "Chuck overboard" , "scrap" , "'Throw away, cast overboard (8)'" , "Abandon, discard" .)