Tons with money problems (7)
I believe the answer is:
trouble
'problems' is the definition.
(I've seen this in another clue)
'tons with money' is the wordplay.
'tons' becomes 't'.
'with' means one lot of letters go next to another.
'money' becomes 'rouble' (currency of Russia).
't'+'rouble'='TROUBLE'
(Other definitions for trouble that I've seen before include "Disturb; unpleasantness" , "Pains" , "'Care, distress (7)'" , "Effort - (cause of) worry" , "Jam" .)