Why Did My Distributor Fail And How To Fix It?
This Tech Tip is one in series that we publish to help people who own or maintain industrial engines. This Tech Tip focuses on the Ford 172/192 distributor drive rod.
While most of the engines we deal with are diesel powered, most of our gas engine customers are still running older Ford or Continental industrial engines. This industrial engine was used in many application including Hyster forklifts, wood chippers, amusement park trains and other industrial applications. The Ford 172 and Ford 192 engines were, and for some continue to be reliable four cylinder industrial engines that have been in service now for over 50 years. We support Ford engines with both hard to find parts such as new distributors and also tech support.
In the last several years we have seen many engines fail because of a worn distributor or a failed distributor drive rod. On a Ford 172 or Ford 192 the distributor drive rod performs a very important function. This Ford 172 distributor drive shaft is a hex sided shaft made of hardened steel, 3.93” long with chamfered ends. This drive rod connects the distributor with the oil pump. The Ford 172 or 192 engine’s cam gear drives the distributor which then, through this short shaft, drives the oil pump. When rebuilding a Ford 172/192 Industrial engine it is good practice to change the rod. A worn or loose rod can result in no lubrication from the oil pump and quickly cause the engine to fail with catastrophic results. Ford recognized this and for many years sold this drive rod under Ford PN D7JL6A605A. Unfortunately, the Ford 172/192 engine drive rod is now obsolete and no longer available from Ford. But here are two alternatives.
- Ford 300 Distributor Drive Rod. The Ford 300/CSG649i distributor drive rod is dimensionally much the same as the Ford 172/192 drive rod except that it is longer. You can cut it down though to the same 3.93″ length as the Ford 172/192 drive rod. We recommend that you use a torch to cut the Ford 300 rod to length and quench the flame in a container of oil. If you quench the red hot rod in a container of water it will cool the metal too quickly and become brittle. After you reduce the Ford 300 rod down to the shorter length of the Ford 172/192, simply touch up the new ends on a belt surfacer. Typically the hardened ends take all the stress and after many thousands of hours of service they will fail. When this drive rod fails, metal fragments get sucked into the oil pump and then into the lube oil system. The result is a damaged crankshaft. We urge any one running a Ford 172 or Ford 192 to periodically inspect their distributor for play in the shaft and also to inspect the condition of their distributor drive rod. If it looks questionable, don’t wait for a failure; or
- Hex Key. You can also take a ¼” hex wrench and reduce it to the same 3.93” OAL dimension and touch up the ends to provide a rounded surface.
We stock some popular replacement components for Ford Industrial engines on our website and if you can’t find what you need there, we stock far more in our warehouse; just give us a call at 866-821-2454 or e-mail us at Info@FoleyEngines.com.
