That’s the rudiments, but there’s more. When shopping for rod ends for your race car, you’ll often come across “commercial” or economy models. Although there are a number of different economy rod ends available (that’s where most of the Far East imports come into play), the only type you should even think about for a serious application are the fully swaged, two-piece models. On these rod ends, the body is formed (or “swaged”) around the ball so that the race the ball rides on is actually part of the body. When looking at inexpensive rod ends, this is the only type that offers decent radial or pull strength coupled with good axial strength (axial strength is the resistance of the ball being pushed out of the side of the body).

Real rod ends use a three-piece precision design. In this application, the race is formed around the ball and then the race insert is staked into the body. Why is this important? Simple. This type of construction offers a much closer fit along with a much higher degree of precision between the ball and the race. Quite often, this three-piece configuration is called an “aircraft” rod end. The three-piece design allows different materials to be incorporated during the construction process. In turn, this allows the rod end to best match the application. Races can be made of mild, alloy or stainless steel (brass or aluminum bronze is sometimes used, but should be avoided because of its low strength) and bodies are made in mild, alloy, stainless steel, aluminum or even titanium.

Teflon Lubrication …

Another common option on rod ends is a Teflon liner. This allows the rod end to be self-lubricating. This is important, since it’s usually difficult (if not impossible) to grease or oil a rod end once it’s installed on a car. But more important is the fact that grease fittings can physically weaken the rod end (a good comparison is a common universal joint with a

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grease fitting—so called “lubable” joints are far more fragile than solid examples). Of course, grease on the rod end ball also attracts grit, which works its way between the ball and race, actually accelerating wear.

A Teflon liner eliminates most, if not all of these circumstances. By design, a Teflon liner consists of a carrier component, usually a fabric (which provides compressive strength) and a Teflon component for lubricity along with various bonding resins. The Teflon liner is bonded to the race so that the ball actually rides on the liner. The movement of the ball rubs Teflon on the ball which, in turn, provides lubrication. Typically you can purchase two or three-piece rod ends with Teflon liners. When looking at Teflon-lined rod ends beware of inexpensive examples with virgin Teflon. It’s relatively soft (approximately 10,000 pounds PSI compressive strength). Meanwhile, a high quality composite Teflon liner will have a compressive strength of somewhere between 40,000 and 60,000 PSI. You’ll also find that a good Teflon liner eliminates clearance between the ball and race, which in turn, makes for a tighter fit.

This Aurora rod end has a composite Teflon liner (usually, you can purchase two or three piece rod ends with Teflon liners). By design, the liner consists of a carrier component, usually a fabric (which provides compressive strength), a Teflon component for lubricity along with various bonding resins. The Teflon liner is bonded to the race so that the ball actually rides on the liner. The movement of the ball rubs Teflon on the ball which provides the lubrication.

Of course, simply adding a Teflon liner to a rod end doesn’t insure precision or performance. One term you’ll come across when dealing with rod ends is “beating out”. What this refers to are usually a couple of distinct problems. The first is the deformation of low strength “self lubricating” liners. You see, some “econo rod ends” have races that are constructed with molded plastic (occasionally mixed with a fiberglass filler). Teflon may also be added for lubricity. These units have a compressive strength of no more than 15,000 PSI. This causes the race to deform long before the body sees any damage.