You should open it up and find out if everything is in place and secure. Our xrx-24s made a horrendous noise for a few months, and we ignored it at our peril.
When it finally stopped working all together, I opened it up to find that the sheet metal "cage" that traps the reducer gear set in place was missing two screws. Guess they fell out due to vibration, although the two that remained were still completely covered with red loctite and very secure.
The result was that the shaft of the reducer eventually worked its way out of its socket because it was no longer trapped in place. When that happened the steel motor drive gear (connected to the worm gear) shredded the nylon gear of the reducer.
Have you found a supplier for parts? Or has anyone given upon repairing there machine? If so, could I have your reducer gear set?
If you open it and need help you can post that as well and I'll try to walk you through it.
ME MMDG
April 2009