Energy Suspension's new 3 piece design Tension Rod bushing for the Nissan 300zx is now on the market. This three piece design will relieve stress on the lower control arms that some of the originals were having problems with.
The stock nissan tension rod bushing is a liquid filled bushing. With age the bushings will crack and all of the liquid will escape. The typical sign when this occurs are the bushing being wet, this will cause vibration under braking and play in suspension.