[ultraman]

i need to know how to insert the idler pulley to put tension on the belt.

[libertyappl]

Hi,
There should be some slots or holes in the base to the front of where the motor sets. If you have your belt around the tub and the motor pulley place the idler pulley in the slots with the pulley toward the drum. The pulley presses against the belt.
Hope that helps.

[richappy]

With the grooved side of the belt on the drum surface and on the wear line, you will find there is only one way to rout it around the idler pulley and motor to get proper tension.
If you don't want to break the belt, turn the drum one revolution to make sure the belt will not jump off the pulley due to misalignment.