My stackable Whirlpool dryer is model no. MLE2000AYW. It squeals when running sometimes. What could it be and how can I fix it?

Your belt might need replaced or adjusted.

Asu22 - I will give you 5 reasons of the proable reasons for your trouble The most # that are the trouble causes, #1- FAULTY DRUM SUPPORT SLIDES :: #2 - NOISY SUPPORT ROLLERS:: #3- THE MOST REASON _ DRY DRUM BEARINGS ::#4- NOISY IDLER PULLY :: #5- SOMETIMERS- LOOSE BLOWER:: #6- this is one that will happen one time in a thousand times ( WORN DRUM BELT :: BUT IT IS USEALLY A THUMPING SOUND:: . #3 has been the cause most of the time ; I have found several on this site and had them to put a HIGH TEMP GREESE IN THE BEARINGS AND IT HAS HELPED :: IT DOES FOR A FEW MONTHS:: THEY BECOME DRY FROM ALL THE HEAT THAT IS ON THEM ALL THE TIME ::
#2 AND 3 -GREESE the SUPPORT SLIDES AND THE DRUM BEARINGS
#4- Check the idler pully for a lot of wear and dry , May have to replace roller, GREESE::
# 6 - CHECK THE DRUM BELT FOR BADLY WORN PLACES AND FOR SPLITS AND CRACKS IN THE BELT ( BREAKS ):: IF There IS REPLACE THE BELT :::
#2&3 - To get to them you will have to raise the top of the dryer and remove it ,( FIRST OF ALL LETS DIOSCONNECT THE POWER CORD AT THE WALL RECEPTICAL ), NOW lets remove the dryer front cabinet panel :: THE DRUM can now be removed , NOTE ( ON SOME MODLES YOU CAN NOT REMOVE THE DRUM Until YOU MUST FIRST REMOVE THE DRUM SUPPORT SLIDES LOCATED AT THE FRONT OF THE DRYER CABINET :IF YOU Don't HAVE TO DO THIS <THEN YOU SHOULD BE ABLE TO LIFT FORWARD AND OUT { OTHERWISE YOU DO THIS AND THEN ON THE BACK END OF THE DRYER THERE IS A BEARING ACESS COVER PLATE <REMOVE IT AND IT WILL FREE THE SHAFT THEN JUST LIFT AND OUT THE DRUM :: While it is out do all of the greeseing and checking of the IDLER
ROLLER AND PULLY & GREESE :: :: OH BEFORE REMOVING THE DRUM YOU WILL HAVE TO REMOVE THE DRUM BELT TO REMOVE THE BELT :: PUSH THE IDLER ARM FORWARD AND ALLOW THE BELT TO SLIP FREE <THEN PULL THE BELT OVER THE TOP OF THE DRUM FORWARD:: ( NOTE _ TO KEEP THE DRUM FROM SAGGING <BLOCK IT UP ON THE FRONT :: PUT BACK TOGREATHER BY DOING THIS IN REVERSE :: GOOD LUCK AND GOD BLESS :: F.B.E.