Forklift trucks are the overburdened packhorse of the warehousing business. They're driven too fast, subjected to shocks and collisions and overloaded-and yet they're expected to never fail.
"You can't prevent things from happening," says Michael Toering, manager of OEM parts marketing group for Houston-based Caterpillar Lift Trucks. "There's no such thing as 'preventative' maintenance."
The fact is that forklifts are a hefty investment, especially for companies that have to maintain large fleets. It's imperative for them to learn how to get the most out of their investment by maintaining the "health" of their lift trucks.
According to statistics, only 20 percent of warehousing operations have any kind of maintenance program and those that do are only performing the maintenance 50 percent of the time at the designated time. Too often, the norm is "maintenance by crisis," where companies wait until trucks break down before they do any kind of inspections. Companies need to break this cycle if they want to see a lower cost of ownership for their trucks. The manufacturers suggest they develop a "Planned Maintenance" mentality, where companies perform inspections on a regular basis to reduce the possibilities of cascading failures in their lift trucks' systems.
All manufacturers provide recommended maintenance periods in their service manuals. However, many operations may need to adjust these suggested PMs in order to fit their working conditions. "For example, some warehouses maintain three shifts of operation," says Wayne Wilde, director of training and technical publications for Nissan Forklift Co., Marengo, IL. "PMs may need to be increased because of the work hours their trucks are subjected to."
The experts agree that PMs should be done based on hours of usage (hour meters on each truck indicate how long they've been operating.) However, even that's not an infallible method, says James Clark, director of service and warranty for Nissan. He suggests doing PMs every 200 hours or 30 days, whichever comes first. The reason for this, he says, is that some trucks may only have "short run usage," where the engine runs for a short time and never gets up to a full operating temperature. "This leads to the buildup of moisture in the engine and the oil never gets to a temperature where the engine evaporates it." This situation may dilute oil lubrication in the truck, which accelerates engine wear.
The PM Process
A PM should take about an hour to perform on a lift truck, says Jim Fisher, of J&P Fisher Enterprises LLC, a West Chester, OH company that provides forklift consultation advice. "It should also consist of more than just a grease job and an oil change-that's only a minor part of a PM."
According to Fisher, the PM should also consist of a complete physical examination of the truck, including both visual and operational tests on the unit to ensure that all of its systems are in good working order. The technician performing the PM should make sure to speak to the lift truck operator and ask them how the truck has been running. "They have their finger on the pulse of the truck," Fisher explains.
The technician should not only change the engine oil and oil filter (for internal combustion vehicles), but also check to make sure the lift chain linkages are tight, that the forks aren't dragging on the ground and that all mast rollers are intact. They should also make sure that both brakes are working properly on the truck (two breaks are required to provide sufficient stopping power). Lubricating the vehicle is important as well-pivot points, axles, pins and bearings must all be well-lubricated.
In addition to checking the fluid levels on all systems, technicians should also make sure to replace the vehicle's hydraulic fluid and filter, according to specified intervals. Otherwise, contaminants that get in the fluid, such as metal shavings, could damage the system's electric or electromechanical valves-an expensive repair job.