The lyrics of Bob Dylan's “The Times, They Are A-Changin'” are often as relevant today as when he first sang them in 1964. For many producers, given the ever-changing requirements of balancing capital ownership costs to a ready-mix truck's useful life, Dylan's lines are prophetic.
When the U.S. EPA's Jan. 1, 2007, more stringent Tier 3 emission standards became law, producers witnessed revolutionary changes in the diesel engine design, projected fuel use, and power torque tables. But in a business climate where margins are already tight, producers must think carefully about their capital purchase plans.
As the supply of the older chassis diminish, producers are feeling pressure to upgrade to chassis with the new low-emission Tier 3 diesels. But that's an expensive proposition. And there are concerns about the new technology. Many producers just are not ready to switch from the old engine styles to the new. Fortunately, they have an option.
Many producers have opted to upgrade their fleets with glider trucks. Retrofitting existing equipment allows fleets to spiff up the appearance and maintain performance levels. In many cases, this option happens without draining capital funds. Perhaps just as important, the glider option offers a short period of adjustment, or an opportunity to ease into the new technology while staying productive with an upgraded, older fleet.
Gary Koomler, the Terex Roadbuilding supervisor of glider trucks and repairs, confirms that rebuild technology is currently a big issue. Producers can rebuild a mechanical engine without penalty.
Something old, something new
Building a glider truck involves taking viable components from an existing mixer and incorporating them into a new frame. The new chassis has a new cab, electrical system, hydraulics, and air components. The customer supplies the engine, transfer case, transmission, drive axles, drum-drive gearbox, and possibly the hydrostatics—whatever can be reused from an older truck.
How does a customer determine exactly which older components to reuse in a glider? Look for older parts that aren't rusted or severely worn, and—especially with engines, pinions, yokes, and drum drives—make sure the seals are good,” Koomler says. He adds that Terex will replace seals for customers as long as a component is in good enough condition.
Terex does whatever is required to get that component up to snuff for glider installation. It's also common for Terex to send an engine back to the engine manufacturer to redo the seals and gaskets, the rear main, and whatever else needs updating. The manufacturer then sends the engines back to Terex to complete the process.
If, instead of reusing just the old components, a customer wants to upgrade a part—perhaps, to go from a manual fuel pump to an electronic one—manufacturers often have programs enabling them to go back to the OEM and get the desired upgrade. All of this is figured into the cost.
“When customers send their mixers to us to ‘glider out,' we can either disassemble their truck for them, or they can do it themselves beforehand and send us just the components,” Koomler explains. “Either way, we put the components on our assembly line with our new trucks and build a like-new truck using those old components. The truck then goes back to them, ready to pour concrete.”
Using the same assembly line and the same craftsmen makes it easy for chassis manufacturers to follow the same quality-control standards for glider trucks that it applies to its new trucks throughout the assembly process.
Mechanics start by reviewing what is needed on the repair. “The first thing they do is prep the components in the repair department,” says Koomler. “The mechanics also make any alterations that may be necessary due to manufacturer updates. Once the parts are approved, the new glider and its components are queued on the assembly line just as if it was a new truck. Mechanics install new brakes, new seals, and anything else needed to get the truck back into full productivity.”
Glider kits differ from factory-assembled glider trucks, as they don't provide the whole mixer assembly, including the drum and superstructure, on top of the chassis. The customer must supply this. Terex simply sends a new chassis, and the customer installs his old component, perhaps with a new drum, if the old one is too thin.
Do-it-yourself doesn't mean go-it-alone. Glider manufacturers offer technical support to customers who decide to glider out a truck themselves. For instance, factory technicians often are accessible by phone to guide a customer through a particularly complex assembly situation, especially when it comes to electronics. Diagrams or instructions can be faxed or e-mailed.