Dat510z

In my care, it was due to bending of the T/C rod. Having urethane bushings on both sides significantly reduces the T/C rod's ability to move up and down with the suspension. My T/C rod broke at right at the point where the shaft steps down to go through the bushings, due to bending. There's a fairly sharp corner there. When I machined my T/C rods to add caster, by moving the shoulder back a few mm, I added a better chamfer there. Yes, Urethane Bushing in the front position (as in relation to the front of the car) and OEM rubber in the rear. This way the urethane bushing will reduce the rearward motion of the wheel, and the rubber bushing will still allow the T/C rod to move up and down.

Yes, on the Z the urethane bushing would be in the "front" position, to limit the rear-ward movement of the wheel under heavy braking and/or suspension movement. There's also "old school" T/C Kit, which used a Delrin and Aluminum cup type "ball pivot" design to replace the "Front Position" Bushings. I still use that style on some of my cars. Experimental Engineering reproduced them using a UHMWPE for the Ball instead of the Delrin (which was more susceptible to degradation). Carter B. used to be the distributor for Experimental Engineering.

Great Thread, one of my favorite to follow. I noticed you show urethane bushing on both front and rear positions of the T/C rods. At least here in the States, myself and others have experienced bending and breakage of the T/C rods, when using urethane bushings in both the tension and compression positions. ( In my case on a 510.) Dual urethane bushings make the joint so stiff it forces energy into the TC rod, causing to bend. In my case replacing the Rear bushing (rear in relation to the car) with a factory Rubber bushings allowed the joint to flex enough without bending the rod, while still gaining the advantage of more stable wheel positioning. Other solutions I've seen has been drill holes radially in to the compressing bushing to allow more compression of the bushing. Given the 240Z has rear facing TC rods, I would think you would want the Front Bushing to be urethane and the Tension Bushing (rear) to be Rubber, (Opposite the 510) Just thought I'd pass the info along. I'd hate to see this beautiful Z you are building, damaged for any reason.

I'm intested in the Tach.