I have seen quiet a few spherical bearings go bad quick, but have also seen them last with no free play. Normally, Are they supposed to last long time. These were parts made from known quality companies and installed properly. Anyone have good experience on reasons their were failing?

 

Normally?

It really depends on usage and conditions. If it is a high stress location, they can fail sooner. If the bearing isn't protected from the environment (dust caps) and the environment is sandy and gritty, they can fail sooner.

Quality rod ends with teflon and such last longer than cheaper ones w/o.

FK Rod Ends- Home Page and aurora are good sources.