From the Picture, it appears to be grooved and if its the stock one, from 98 is more then likely doesn't have much time left. Those Plastic POS ones they put in stock like to lock up and burn off belts along with causing other problems. I got a brand new aluminum one at checker for 10 bucks I think?? Can't remember since its been so long. I get parts cheap though.
Just trying to be helpful. Thats why I asked also if it squeeked yet.. Sorry if I seemed... obtrusive?