Replaced cushion mounting ring and gaskets, but the leak was around the sink flange. Took it out, cleaned everything, put in new putty then tightened everything down wobbling the disposal while tightening the collar to squeeze the excess putty out from under the flange. If you just try to squeeze out the putty by tightening the collar you'll probably break the collar or strip the threads on the flange extension under the sink. Just do it slowly, wiggling and then tightening a little until the lip inside the sink gets down flush.