Crash is pain? That's about right! (5)
I believe the answer is:
prang
'crash' is the definition.
(to prang is to crash a car)
'pain? that's about right' is the wordplay.
'pain?' becomes 'pang' (pang is a kind of pain).
'that's about' indicates putting letters inside.
'right' becomes 'r' (common abbreviation).
'pang' going around 'r' is 'PRANG'.
'is' is the link.
(Other definitions for prang that I've seen before include "Car accident, usually not too serious" , "Minor accident" , "Crash involving a car" , "Crash (a motor vehicle)" , "Plane or car crash" .)