Very big shock absorber (6)
I believe the answer is:
bumper
I believe this clue is a double definition.
'very big' is the first definition.
(as in a bumper crop)
'shock absorber' is the second definition.
(as in a car bumper)
(Other definitions for bumper that I've seen before include "Exceptionally prolific" , "Exceptionally large" , "jumbo" , "Something big" , "Protective vehicle bar" .)