By Steve Sniff

In this article, we will explain what a final drive is, why heavy equipment can’ t live without it and why we should remember it … regularly.

What Is It?

In its simplest form, the final drive is the last gearset in the drivetrain that delivers power from the engine to the ground. The way this power is delivered is by converting engine speed into torque through a series of speed reductions. These are accomplished by a number of gearsets at various“ worksta- tions” along the drivetrain. The very last, or final, one of these work-stations is the final drive, that is, it is the last point of contact before the power enters the wheels or the tracks and moves them on the ground.

The reason these series of step-downs are necessary is because even a large, strong engine cannot, on its own, turn the wheels or tracks. Trying to do so is analogous to trying to cut through a grade 5 bolt with a pair of garden pruners. It just wouldn’ t happen. But at 4,500 foot-pounds, a pair of bolt cut- ters can leverage the power of a person’ s arms through very long handles and focus all that power down into a tiny set of blades, barely big enough to fit around a bolt, and slice through it with relative ease.

Similarly, gear reductions are used to convert a bulldozer’ s

400-plus horsepower into enough torque to move that 100,000-pound machine, and to do so with relative ease.

The final drive is a critical component in that conversion, it being the part that actually turns the wheels or moves the tracks. However, it often gets overlooked when it comes to care and maintenance, due in part to the fact that many operators who are not mechan- ics don’ t really know what it is,

40 November 1, 2024 www. contractorshotline. com