How to Fix Chassis Bind

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Plenty of racers chase chassis handling-hooking issues and never once consider the effects of chassis bind. Chassis that are bound up don’t work. Period. There are a lot of causes for chassis bind, but the first thing to look for is a bound up rod end (or “sets” of rod ends). Here’s why:

When a pair of rod ends is used in a single component (using a four link bar as an example), the orientation of the rod ends on either end is important. This is what chassis builders refer to as “clocking” the rod end. Stop right here for one second: When you make very small adjustments in a suspension link that sees pre-load, it turns out you can make a huge difference in the way the car works or handles. According to Pro chassis builder Jerry Bickel, one-sixth of a turn at a time is all that is required in order to see a change in the way the car works. Keeping this in mind, counting the number of “flats” (the flat side of the rod end jamb nut) you turn on a link is critical. When you make those adjustments, you can inadvertently place the link (and the rod ends) into a binding condition.

Attached are a couple of illustrations (courtesy of Jerry Bickel Race Cars). The first one shows you how a typical link is configured: One side of the link is fitted with right hand threads while the other end of the link is fitted with left hand threads. By simply loosening the jam nuts, you can lengthen or shorten the entire four-link bar.

What about clocking? It’s easy – see the second illustration (again, courtesy of Jerry Bickel Race Cars). When the rod ends are properly “clocked,” they are aligned. When the rods ends are aligned you won’t encounter binding in the suspension. At the same time, a link with clocked rod ends makes it easy to determine if the link is under tension. Simply grab the link by hand and rotate it back and forth. You’ll be able to tell if the link is neutral or under load. Here, you want the rod end to be “neutral.”

The bottom line here is, take the time to check all suspension members to insure that the rod ends are properly clocked. It doesn’t take much time and it can have a huge effect upon how your car functions.

Rod ends used in conjunction with four link bars (as shown here) should be “clocked.” That means you should align them after adjusting (or otherwise changing) the link length.

(Credit: Jerry Bickel Race Cars): When you adjust something like a four link bar, you loosen the jamb nuts on each end and turn the link (bar). That moves the link in or out. It can also change the orientation of the rod end once you re-tighten the jamb nuts. Each rod end can become “clocked” or twisted sideways.

(Credit: Jerry Bickel Race Cars): What you need to do is to “clock” the rod ends when you’ve completed the length adjustment on the link. This illustration compares a clocked rod end to one that is not clocked. Properly clocked rod ends on a given link allow the rod end to function without binding.