The special tool used at the dealership is used to measure digitally that the timing belt is correctly tensioned. Volvo give precise specs for belt tension. My information shows this is an interference fit engine (valves will be damaged if the timing belt breaks. Labor to replace the belt is between 2 to 2.5 hours.
no if your old timing belt is not broke just put your motor in time and take off your automatic belt tensioner but make sure you use white out and mark two lines on both cams and one line on the crank this will insure that your motor will be in timed right I have 16 years in auto experiance I have my own bussiness and i work at a auto repair shop