My Performa Washer is about 10 years old and we love it. I've replaced the pump and the motor on it and it's still going strong, but now the agitator is not advancing. I removed the agitator to clean out the old fabric softner build-up and when I reinstalled the agitator I thought I put it all back the same as I disassembled, but apparently not. Now, during the wash cycle, the agitator will move forward about 1 inch, then back 1 inch, then forward the same inch again. It does not advance and therefore the clothes in the tub are not being rolled from top to bottom as they used to be, they are just being swished back and forth and thus are not being cleaned as they were. I've read through the maintenance manuals but can't really see what might be causing the problem. Any suggestions? Thanks in advance.