Dryer Squealing from the tension pulley

I have a Maytag Bravos Quiet series 300 dryer, It started squeaking every now and then. Eventually it got to the point where the squealing was constant. I took the drum out and removed all 4 rollers, cleaned them and made sure they were turning freely. lubricated the bushing with WD 40. I put it back together and the noise was still there. I then took the tension pulley off, cleaned it, used WD40 and put it back together. The noise went away and a couple days later it was right back. This time i took the tension pulley off and put grease on the pin and bushing. so far so good but its only been a day. What is the proper grease / lubricant to use on the tension pulley and the rollers? I also broke the small plastic triangle keeper for the tension pulley. I've used a bobby pin as a temporary fix. Is there a circle clip that I can use as an alternative to the triangle plastic piece? I'm sure home depot doesn't sell those.