Product review (4 stars): Stops Dryer Squeek
We've had our dryer for over twenty years.  The glides and the belt are the primary wear items.  Along the way the motor and heating element have also been replaced.

When the tumbler begins to squeek and doesn't turn freely, that's a sign that these glides need replacing.  With this kit it's easy and inexpensive to do.  This must be a generic glide kit, however, because the nylon tabs need to be trimmed, preferably with a Dremel, to get them to fit into the slots in the dryer front panel.  A tube of contact cement is provided.  I preferred to use heat resistant grey silicone gasket maker adhesive.  Cleaning off the old adhesive and felt is best done with a wire brush mounted in an electric drill.

A great way to keep the old dryer running.  Why buy a new one?