Managing to insert fastener in gearwheel (6)
I believe the answer is:
coping
'managing' is the definition.
('cope' can be a synonym of 'manage')
'fastener in gearwheel' is the wordplay.
'fastener' becomes 'pin' (pin is a kind of fastener).
'in' means one lot of letters goes inside another.
'gearwheel' becomes 'cog' (I've seen this in another clue).
'pin' put inside 'cog' is 'COPING'.
'to insert' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for coping that I've seen before include "wall feature" , "Contending with - wall masonry" , "Contending successfully" , "Doing well" , "Rubbing along" .)