Product review (1 stars): Poor engineering of Exhasut Fan.
Maytag used the cheapest way to drive the exhaust fan for this dryer and it will fail in service.  The exhaust pulley will fall off the fan during regular use.  You will have remove the front, and probably the back panel to put the pulley and drive belt back in place.  There is no way to make the pulley secure other than to epoxy it in place.

There are four ways you can secure a pulley to this dryer's exhaust fan:

1 - a spline or a square shaft

2 - a key way, a groove in the shaft with a tab in the pulley to transfer the force from the motor.

3 - a threaded shaft and pulley pulley that screws onto the shaft secured by a cotter pin or set screw in a flat spot or keyway.

4 - a threaded shaft as above secured by a lock nut

Or you can do what this manufacturer did:  The pulley is just a big nut with no locktite or glue to keep it from coming lose and the drive shaft threads are so short you can not put a lock nut to correct this poor engineering.