there was a recent answer that might help. The belt goes around the drum, grooves in, then passes under the idler wheel on the tensionser. This slots into two grooves behind the motor, with the flange to attach the spring facing towards the middle of the dryer. The other end of the spring goes around the switch in the middle of the base of the dryer.
This is best done with the dryer on its face and I find a bit of electrical tape to hold the belt around the drum while I rethread it works well. Make sure the grooves on the belt go inwards around the motor pulley.
Angus, October 2006
