I purchased this new drum for my Sharp AL1631 copier that gets light usage, less than 30 copies per week.  It worked fine for a week then started leaving blank areas on copes down the center of the page.  In addition to that, the end of the unit fell off and two gears fell out.  It took me a while to figure out how to reinstall the gears to make the drum work, but the blank spots continued.  I thought that it may be the new toner cartridge that I had installed at the same time, but even after purchasing a second new toner cartridge, the blank spots are still there.  The first 2 or 3 copies are fine, then the blank gets wider and wider.  I finally decided to just buy a new copier and stop spending money on new parts and supplies.  Of course, this was what I was trying to avoid in the first place.