Dryer making and rumbling,grinding noise

what could possibly be causing this? is it the bearing or something diffrent any help is much appreicated thanks in advance

Here is the parts breakdown
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=dbxr463ed2ww

Yes it could be the rear bearing.

Other things to check are the front support slides and the idler wheel.

Only wat to tell is to open it up.

Here is a good link that may help
http://www.applianceaid.com/dryers.html