Hayward 1000 pool pump leaking ( Diffuser Gasket)

I just replaced the seal and the diffuser gasket in my Hayward 1000 pool pump. This is the first pump that I have worked on that has a diffuser in it, The pump was leaking pretty bad so I ordered a new seal kit for the pump.
When I was taking it apart I noticed that there was a big rubber gasket that was all chewed up, I found out later that it is for the diffuser, I don't know what chewed it up so I went on line to you tube and found a site telling me how to replace the new seal and the diffuser gasket. I did just like they said and put it all back together and I have still got a big leak.
So I got back on line and looked at another you tube site and this one said to lube that gasket that goes on the diffuser well I didn't do it cause I wasn't told to.
So I guess that the new gasket is all chewed up again. I will pulling it apart tomorrow to see. So is it leaking because I didn't lube the gasket.?