Should The Back Of A Mower Deck Be Lower Than The Front?

With everything you have to know and do, the start of the lawn mowing season can feel a little like "ready, set, go." You've checked the oil, topped off the tank, and even the mower deck wheels are set at the right height. But if you're mowing along and you're still having problems with scalping your lawn or getting an uneven cut, there's one other thing you need to try: Make sure the rear of your mower deck is sitting slightly higher than the front, not lower.

A lot of people assume that the mower deck should be completely level to get an even cut, but a tilt is preferred. There's a physics lesson behind the reason you need about a ¼-inch difference from the front to the back. This is often referred to as the deck pitch or rake, and what it does is create an aerodynamic lift that pulls the grass up for a neater cut. When you combine this technique with other methods for mowing your lawn more efficiently, it's easier to cut your lawn neatly.

When it comes to determining how much higher the back of the mower deck should be than the front, the key is to not overdo it. It should be about a ¼-inch difference from the front to the back, although it can vary from ⅛- to ½-inch, depending on the model. That's a precise measurement, so it's not something you should eyeball if you want the best mowing setup for your lawn.

To check the pitch, park your mower on flat, level ground, and set your mower at a high-enough height to maneuver underneath. Use a tape measure to determine the gap from the ground up to the front blade tips, then measure the gap from the ground up to the rear blade tips. The difference between those two measurements should ideally be about ¼-inch, or anywhere in that ⅛-to-½-inch range, with the lower measurement at the front of the mower.

Whether or not you can adjust your lawn mower's pitch depends on the model. For many, this is a built-in feature. If you are able to adjust yours and you overdo it with too much pitch, you're likely to end up cutting your grass too low, which weakens it and opens the door to weeds.

Even with the pitch on your mowing deck set perfectly, there are other factors that can affect the rake and leave you scalping the lawn. Terrain and tire pressure are the two big ones, and they can throw the pitch off even on mowers where it's built in and can't be adjusted. If you can adjust the pitch, dialing it down when you're mowing on uneven slopes or terrain with dips will make it easier to avoid gouging your lawn.

Tire pressure is the other main lawn mower problem that could be causing the wrong pitch, and letting it slide is one of the accidental ways you can damage your mower. This one can sneak up on you, but checking tire pressure, tread, and condition is actually something you should do regularly and one of the first things you should check to improve your mower's cut quality. It's also important to check the tire pressure before you make any adjustments to the deck or the blades, since it can throw off a reading measurably.