I cannot figure out where idler arm shouls sit on neptune dryer and wher spring goes.
Here is a parts breakdown
Replacement parts for MAYTAG MDG3000AWW Dryer - Gas | AppliancePartsPros.com
One of the following may help
http://forum.appliancepartspros.com/dryer-repair/25860-dryer-belt-diagrams.html
http://www.servicematters.com/maytag_library/docs/16023110.pdf