My 5 year old Maytag drier squeaks something awful when we turn it on -- its so loud I can hear it outside. My husband took it apart and used a heavy duty non silicone spray on the wheel that makes the drum spin, but it only stopped it for 1 cycle. Otherwise there's nothing wrong with it.

I don't want to replace the dryer, what can be used to stop the awful noise?

Its either the rollers or the idler pulley
Make sure the roller posts are clean. Light sanding and make sure the rollers spin free. Also dry the silicone off. No grease or oil on those. Lint will collect on the oil and make it worse.
The idler pulley is common to squeak. It's the pulley that keeps the belt tight. If removed study how the belt goes around it. Maytag's are tricky getting there belts back on.