Search the archives of this group for a nice man in Ovid, NY who repairs and sells parts for Maytag wringer washers. You may wish to contact him and see what advice is offered.
There is a safety mechanism that causes Maytag wringer roller to pop open if the machine senses something took thick is being pulled into the machine. Designed to prevent arms or other body parts from being harmed the system can also be triggered by say a too thick blanket or quilt. http://www.automaticwasher.org/cgi-bin/TD/TD-VIEWTHREAD.cgi?91
It could be something is out of whack or worn out with the tension system in yours that needs attention.