I have an older White Westinghouse dryer. It has worked for over 8 years just fine. Two months ago the drum quit turning and I had to replace the belt and the idler pulley. The belt was stretched and frayed and the ilder pulley had slipped completely off and fallen onto the wheel that is turned by the motor and been gouged. It worked fine until a few days ago when the drum quit turning again. The belt had slipped off so I put it back on. The dryer would run for a little while and then it would slip off again. I adjusted the tension on the spring several time thinking it needed to be tighter. It ran OK for about three loads and then the belt snapped completely. I purchased another belt thinking perhaps I had bought an inferior product, put it on, and it ran for about 30 seconds and snapped. I can't figure out what is wrong. Everything is installed correctly, the pulley is new, and the belt is threaded correctly. Any suggestions would be appreciated. Thank you.