I have a 1985 Winnebago with 56,000 miles on it with a 454 engine. The belt that runs the alternator and air/smog pump keeps wearing out and breaking after only 500-1000 miles. I have replaced the alternator and air pump, checked pulley alignment, and have used two different brand belts with no improvement. I check/adjust belt tension regularly, but the belt squeal keeps getting worse and worse till it finally breaks. I've changed it so often, I can change the belt in 20-30 minutes start to finish, but it's not fun. Would appreciate any suggestions and help.