Chuck Schultz is a licensed engineer, Gear Technology Technical Editor, and Chief Engineer for Beyta Gear Service. He has written the "Gear Talk with Chuck" blog for Gear Technology since 2014.
Modern cars and trucks are wonderfully reliable and durable. As much as I love old cars I cannot cleanse my memory of the heartbreaking behavior they inflicted on the motoring public back in the “good old days” unless they were religiously maintained. The 3,000 mile oil change interval was ingrained in young drivers because the vehicles burned and leaked oil almost immediately after the 12,000 mile warranty was up.
We old timers like to remember the freedom those $100-to-$250 cars brought us, while conveniently forgetting the hours spent replacing rusty exhaust pipes. Amateurs replacing brake parts, starters, spark plug wires, clutches, and universal joints in their driveways with $40 Sears tool sets was a regular sight in urban America. Millions of young people had to get their hands dirty if they expected to have a car of their own. When someone says “They don’t make them like that anymore,” I agree — and add “thankfully.”
Our expectations today of durability are much different as well; a car with 50,000 miles on it was once a “back row special” at a dealership; today it is a “creampuff.” If you took the way-back machine to 1965 and told anyone that people would routinely drive a vehicle well past 100,000 miles, they would laugh in your face.
This change in expectations has spread to industrial equipment as well. In 1965 the majority of American industrial gearboxes featured through hardened gears that started to pit the tooth flanks almost immediately. Few of them had pressure lubrication, and even those rarely had any filter on the system. Regular oil changes were the only way to get all that metal debris out of the sump; even top-notch mechanics could not keep those tooth flanks from wearing out.
Today’s industrial gearboxes typically have surface hardened and ground gear teeth. If a “pothole” or even a tiny divot appears on those shiny tooth flanks, we know something has gone seriously wrong. Instead of five-to-seven years of life, our customers can look forward to twenty years or more in most applications.
This doesn’t mean that maintenance is no longer required. Regular oil changes are still the secret to reaching that 20 year mark.