Volvo Repair: 1992 960, dampener, camshafts

Question
Why is the timing belt maintenance interval 92 960 only 30k? Doesn't this seem a bit short?

Answer
I am not sure why it is at that interval.yes it is short.I believe there was a problem with maybe the withd of the belt combined with some vibrations put on the belt by the camshafts.I really am not 100 percent sure.I know they did on this year install an additional dampener behind the exhaut cam pulley to reduce vibrations to the belt.