Should Lawn Mower Deck Wheels Touch The Ground?

The saying "keep your wheels on the ground" originated from motorcyclists, but has also been applied to cars, trucks, ATVs, and just about anything with wheels. This idiom for staying safe can also be useful when it comes to handling your riding lawn mower. But, is it apropos for all of the wheels? In other words, should the little wheels on your riding mower's deck touch the ground while you are mowing? The simple and short answer is, no. However, it is also important to understand the purpose they serve and when they may actually need to touch the ground.

To start with, the small wheels which are positioned on edges of the mower deck are officially called gauge wheels. They also show up on some zero-turn mowers. The purpose of these gauge wheels is not to support the mower deck. Rather, they are there to prevent the deck itself from hitting the ground when it goes over uneven areas. This helps both extend the life of your mower by preventing deck damage, and prevents scalping portions of your yard by letting the blade get too low. However, in order to glean these benefits, gauge wheels have to be set in the proper position when you are mowing. That said, it is important to note that not all riding lawn mowers have gauge wheels, so this is a feature you should look for when buying a new mower.

Properly adjusting the gauge wheels on your riding mower can help prevent scalping your lawn as you mow over high points and uneven surfaces. To do that, they must not be on the ground or too close to it when the mower is on a level surface. Having deck wheels in constant contact with the ground can actually result in damaging your lawn, mower deck, and the gauge wheels themselves through excessive dragging, stress, and friction. In fact, the wheels should have anywhere from ¼-inch to ½-inch of clearance between the ground and the bottom of the wheel. Keep in mind, this distance is from the surface of the soil, not the top of the grass.

There are actually a couple different styles of gauge wheels and each has a slightly different method for adjusting height. But a few basic steps to ensure proper height adjustment are the same. First, move the mower to a flat spot and level the deck side-to-side and front-to-back. Then, set your cutting height and measure the distance between the deck wheels and the ground. If they are within the tolerable range, you're all set. If not, you will need to adjust them to make sure your mower isn't scalping or cutting your grass unevenly. 

On models which have a through bolt holding the gauge wheel in place, remove the nut, bolt, and wheel and set them in the correct hole or slot on the mower deck bracket that places the wheel at the proper height. Tighten the lock nut and repeat the process on the remaining wheels. On models that use a pin and spindle, remove the pin, then slide the wheel assembly up or down to achieve the right height before replacing the pin.