I see this is a old thread. Hoping I can get a reply still. Been digging for a min now.
But are the threads on the spray bars and swivels the same on the hammerheads,Simpsons, and whirl a way? I know hammerhead and Simpsons are the same.
If you break down the swivel assembly the bearings are actually not completely sealed, there is a gaurd on one side of both bearings but were they meet does not have a shield.
This speaks just for the 2 times mine have locked up and I took them apart and changed out with a major repair kit