I have 3 Toto one piece toilets with the large flapper. The chain for flushing the toilet has a link that goes through a rubber piece that is part of the flapper. I have had to replace the flappers several times because the link tears through the rubber. This is under normal use. Nobody is pulling on the chain other then for normal flushing.

Has anybody else encountered this problem and are there any suggestions for how to handle the problem.