We have a brand new sink and we are trying to install our old garbage disposal (Sears Roebock 2003). We have been trying for about 3 hours to get the 3 rings to connect to the mounting bracket. We have tried everything to get them to connect, but they don't seem to want to all connect. It seems to me that the rings are just shy of connecting with the mounting bracket... any ideas... are newer garbage disposals any easier to install than this?

Here's a "how to" link you may find helpful. Installing a Garbage Disposer Tutorial Good luck, Tom

If I am not mistaken, one ring should have notch in it. That notch should slip over the collar holding the other two rings up against the sink. Then, tighten up the screws.

Did you buy a new Disposal ring that goes through the sink, say maybe a different color to match the new sink.
If you did I have had this trouble where you think you have it in place but as you hang the disposal the round steel o-ring comes out. One time I got the new one to work by a filing a bit off one end if that steel ring. And then when you think you have the steel ring in place use a screw driver to tap it on into the little grove.
If you did not replace the thing going through the sink then this may not be the problem.
Let me know if this helped you.