Rattling Check Valve

I have a very loud rattle coming from what appears to be the ortega check valve. This valve is located downstream from a Pentair Clean and Clear 320 Filter. The noise seems to have gotten worse over the past few months since I have started running the pool pump more consistently and for a longer period of time.

At one point I took the check valve apart and attempted to clean and reseat the valve. This seemed to reduce the noise for a few days but had very little impact. I am thinking I just need to replace something but I'm not sure if it would be the spring or the seat assembly the spring rides in. Any help is greatly appreciated!