What known issues are there with bmw arm bushings?
The front thrust rod bushings—also referred to as tension strut bushings—are known to fail occasionally. The oil-filled rubber mounts weaken and crack over time, causing a mushy road feel and shuddering in the steering wheel when going over bumps. These worn bushings should be replaced.
The OEM rubber will go bad on all of the series. There are several aftermarket replacements available depending on your vehicle, and the type of ride you hope to have. Powerflex are some amazing urethane replacements I recommend for track use or if you just want to never replace them again!