GE Multi Orbit Arm

[cam2s]

So I had an opportunity to put the Potscubber III back in service but I seem to having an issue with the wash arm now. The machine sat unused for not quite a year, and now the little washer under the wash arm has kinda dried up. It needs to be able to secure the wash arm to the pump outlet but be slippery enough to allow the wash arm to rotate. No matter what I do, it seems to tighten itself down as the wash arm rotates to the point will it will no longer rotate. Is there a suitable replacement or a way I can rejuvenate this part?

Thanks
Cameron