Volvo: 740 volvo 1987 crankshaft/belts, crankshaft pulley, crank pulley

Question
I replaced power steering/fan belt, I had to remove the alternator and AC compressor belts. I was successful...but...now I notice that CRANKSHAFT PULLY moves causing power steering belt to rub against a plastic cover at the back of the crankshaft and also causing the belt to twist. 1) Do the crankshaft pully suppose to move back and forth? If not how do I bolt it down? 2) AC compressor pully have two grove that belts can go on, Do I use the first or second grove for ac compressor belt? 3) If the ac belt on the wrong grove, would that cause the crankshaft to move?  Thanks. I hope this is clear ..what I am asking

Answer
Tony,
Crankshaft pulley should not move. The outer pulley has come loose from the inner hub and will need replacement. Use the outer groove on the A/C comp. Now would also be the time to inspect the timing belt and seals so you can repair all that is needed up front now while the crank pulley is off.