Vacuum Cleaners Discussions

Hey guys... wondering if you all have any suggestions about a problem I discovered in my Sanitaire SC887 this morning.  I just reassembled the bag/bin compartment after washing it and went to use the machine this morning.  Well, it was about 3 times as loud as it should be and the bag BARELY inflated.  It did, but not firmly and I was able to "squish" it easily with my hands where as before that wasn't possible.  I turned the machine over while running and the it seemed to be running at full speed.  The fan didn't have any broken blades from what I could see without digging into the machine.  When I first got the machine, I took it to the shop to get the height adjust knob replaced and the guy said it needed new bearings too so he replaced them.  It's beein fine for 3 years, but this morning, it's having a serious issue.  Any clues as to what could be going on with this thing?  My ears actually hurt after trying to use it for 5 minutes!