Check Your Heim Joints

One component that is often overlooked in race cars is the heim joint — yet it carries a huge amount of load, especially in the rear end.

When setting up race cars, one of the most common issues we see is loose rear-end heims or movement in the Teflon liner. Any play in the heim allows unwanted movement in the rear end, which can cause the car to steer left or right as soon as you release the transbrake. That small amount of free play can turn into inconsistent and unpredictable launches.

Another critical factor is how far the heims are wound out in the rod ends. They should never be wound out more than ten turns. Excessive extension reduces strength, can lead to bending, and ultimately causes failures and setup problems.

For four-link applications, we use a three-piece male rod end with a ½-inch hole diameter and a ¾-inch thread. These heims are rated to a 40,000 lb load capacity, ensuring strength and reliability under extreme conditions.

We also use aircraft-grade NAS bolts in all of our rear ends. These bolts have much tighter tolerances than standard hardware and are manufactured to create a precise, tight fit in the bolt hole — reducing movement and improving overall rear-end stability.

Attention to the small details like heim condition, thread engagement, and hardware quality makes a big difference in how consistently and safely your car performs down the track.