The other type of liner “beating out” failure involves the physical bond between the liner and the race. The self-lubricating nature of the liner sometimes makes it difficult to bond to the race. If the manufacturer can’t make this bond sufficiently strong, then the liner will become detached from the race. Each time there is a misalignment of the rod end (more on this later), pieces of the liner will disintegrate. The end result will be a rod end with clearances that prove excessive. Aside from government MIL Specs for Teflon-lined bearings, there are no standards set for liner bond strength. Of course, if a rod end manufacturer can meet this standard and manufactures a line of bearings approved for military use, then there’s a good chance that their high quality Teflon-lined race bearings also use this same manufacturing criteria.

Aligned Or Misaligned?

What is rod end “misalignment” all about? Remember when we pointed out the basics of rod end design (the sphere inside the race)? Basically, it’s no secret that a bolt or fastener of some sort goes through the hole bored through the center of the rod end. Because of this, it’s obvious that it cannot rotate inside the housing a full 360 degrees (without the fastener through the center, the ball can rotate through a full circle). Given this fact, all rod ends have limitations in regard to how far they can be misaligned before the sphere binds in the housing. The angle of misalignment is a crucial factor when selecting rod ends. Not all rod ends can accept the same degree of misalignment as others. If you exceed the manufacturer’s recommended maximum angles, the smallest thing you’ll find is premature rod end wear. On the other end of the spectrum, the worst thing you’ll find is outright rod end failure.

Take a close look at this rod end. See how the “ball” isn’t centered? This is the “misalignment” that the rod end design can handle. Check the manufacturer’s recommended maximum angles in their respective catalog, then order the right bearings (different rod ends have different misalignment tolerances). The text offers info on measuring misalignment (it’s simple stuff).

So how do you know how much the angle of misalignment really is? To measure the angles mandated for the application, use a good old-fashioned protractor to dimensionally check the geometry. You’ll find that this angle of misalignment is specified in all rod end catalogs (at least those who manufacture quality rod ends). Comparing your measured angles to those in the catalog, you’ll be able to select the right rod end for the application. The biggest mistakes you can make are to shortcut this measurement and to buy a rod end that simply looks big enough to handle the job.

That’s just the beginning when it comes to rod ends. Next issue, we’ll dig deeper into the world of spherical bearings. You might be surprised at what you see.

Previous Stories

Some Quik Trix from Mr. Wilson  — 5/7/04 Four racing tips that can save you time, aggravation and $$$ Project Muscrate DRO's crate motor Mustang - Part 3 — 5/7/04 Life goes on Bits & Bytes- Part 2 — 5/7/04 Hooking Up An Auto Meter Data Logger