ForConstructionPros.com

When used in reference to transmissions, the term "genuine parts" conjures up images of gaskets, plates and bushings. But these days, its usage has spilled over into discussions about fluids, as well.

"We keep asking equipment to do more and more," says Jack Zakarian, consulting engineer at Chevron. "As a result, transmission fluids are becoming more of a 'genuine part'. They are more like gears and clutches where you can't take one manufacturer's parts and put them into another's transmission. Fluids have become part of the design of the transmission. Many builders consider them a design component."

That's why it's important to use the right fluid for your particular transmission. Manual truck transmissions require different fluids than automatics, and they each require different fluids than off-road, heavy-duty construction equipment with powershift or hydrostatic transmissions. You'll find fluid information for a particular transmission listed in the equipment operator's manual. Work with your oil supplier to match the specification to the product label of any fluids you're considering.

"Using the right fluid will improve the durability of a transmission," notes Dan Arcy, Shell, "whereas the wrong one can mask a problem and reduce the life of the transmission."

Arcy witnessed one such scenario at a car repair shop where shop technicians used tractor transmission fluid to "fix" a shifting problem in a passenger car. "Tractor transmission fluids have a high level of friction modifiers, which caused the clutch to slide," he says. "While those modifiers made the car easier to shift, the clutch ultimately wouldn't hold together and the life of the transmission was reduced."