Firm with transport giving trouble (8)
I believe the answer is:
hardship
'trouble' is the definition.
(I know that hardship is a type of bad luck)
'firm with transport' is the wordplay.
'firm' becomes 'hard' (both can mean durable or strong).
'with' says to put letters next to each other.
'transport' becomes 'ship' (synonyms).
'hard'+'ship'='HARDSHIP'
'giving' is the link.
(Other definitions for hardship that I've seen before include "Severe privation or suffering" , "Adversity, misfortune" , "Difficult circumstances" , "Austerity - affliction" , "Adversity, grimness" .)