How To Troubleshoot A Lawn Mower Deck That Is Not Level

Does your lawn mower produce an uneven cut even in the flat ground? The main reason which is responsible for uneven cutting is the unlevel deck of your mower.

You must be eager to discover if it is feasible to fix this annoying issue and how to troubleshoot a lawn mower with an uneven deck. As part of the troubleshooting process, you will need to check the pressure of the tires, check the height of the deck from side to side and from front to back and finally adjust your blades.

In this article, I will discuss the troubleshooting techniques for a lawn mower deck not level. Continue reading the article to learn how to solve this particular problem.

What Causes Your Lawn Mower Deck Not Level?

How terrible that your mower isn’t mowing the grass equally; a mower deck that isn’t level can lead to a number of problems, including uneven grass cutting.

As a result, identifying the root causes of the problem will enable you to resolve it more quickly and effectively.

A clogged or broken cutting deck, a bent crankshaft, and damaged wheels, uneven lawn ground, unbalanced tire pressure are all possible causes of your mower deck not being leveled.

6 Steps to troubleshoot lawn mower deck not level:

There are a number of answers to this specific problem that you can find on a variety of consumer forums and videos on YouTube. But, several approaches to solutions are not trustworthy and may even be rather expensive to implement. 

Therefore, I have enlisted a step-by-step troubleshooting guide for leveling the deck of your lawn mower.

Things you will need to troubleshoot when lawn mower deck not level:

Adjustable WrenchTape Measure
Half Inch SocketTire Pressure Gauge
Lift Lever 
Nut Driver
Safety Gloves

Step-1: Place in a Plane Ground

Start troubleshooting by ensuring that your lawn mower is on a level surface. The ground serves as a base for your measurements.

Next, remove the key from the ignition. Finally, engage the parking brake and disconnect the ignition wire.

Step-2: Check the Pressure of the Tires

An uneven tire pressure results in an uneven mower deck, causing an uneven cut. Therefore, use your pressure gauge to check the tire pressure and ensure the mower is level so the deck may be correctly aligned.

First, ensure that the pressure in the front tire is set to the amount advised on the tire sidewalls by your mower’s manufacturer. The air pressure in both tires must be the same. Repeat this process for the rear tires also.

Step-3: Measure Height from Blade Edge to Level Ground (Side to Side)

To begin, place the lift lever in the middle position so that it can lift the mower deck to its highest point.

Then, turn the blades to the side and use the tape measure to find the distance from the ground to the bottom of the mower deck. Then, do it again on the other side of the deck.

Carefully take note of the measurements and subtract the two to find the difference between them.

Note: An adjustment to the side is not required if the difference is less than 1/8-inch. However, it is necessary to adjust the blade if the difference is more than 1/8-inch.

Step-4: Adjust the Blade (Side to Side)

Adjust the height of one side of the deck to equal the height of the other side, or set the height of both sides to the same level.

Changing the adjustment components, such as a nut or a gear on the suspension arms or deck hanger brackets, makes it simple to alter the deck height. These components may be positioned at the rear of the deck. However, the location may change over several models.

To raise or lower the deck, use a clockwise or counterclockwise adjustment mechanism. Continue to monitor the height of the deck until you have obtained the ideal level and height.

Step-5: Measure Height from Blade Edge to Level Ground (Front to Back)

In order to measure the height from the blade edge to the level ground, you must first rotate the blades so that they are facing front to back.

Use the bottom edge of the blade that is closest to the deck for measuring the distance between the ground and the front and rear blade tips.

Note: The placement of the blade is appropriate if the front blade tips are 1/8-inch to 1/2-inch lower than the rear blade tips. But the adjustment is necessary for the blade if the front-to-rear angle of the deck is not between 1/8-inch and 1/2-inch.

Step-6: Adjust the Blade (Front to Back)

Utilize the wrench to turn the jam nut in order to loosen it for adjustment. Turning the adjustment nut counterclockwise will loosen and lower the front of the mower, while turning it clockwise will tighten and raise the front of the mower.

Finally, check to see whether the difference between the front and back blade tips is within an acceptable range. Tighten the jam nut when the readings are within an acceptable range. Make sure the adjustment nut does not move while you’re working.


Please read the instructions before doing any work on your lawn mower, whether it’s routine maintenance or major repairs. Always start your work by ensuring the lawn mower is unplugged from the power source.

You can also watch this video.

Frequently Asked Questions

Why is My Riding Lawn Mower Deck Uneven?

There are several reasons that can be responsible for an uneven mower deck. The reasons mainly include damaged tires; a mower blade that is bent, loose, or dull; a crankshaft that is deformed; a mower deck that is clogged or damaged; etc.

At What Height Should I Raise the Deck of My Lawn Mower?

Typically, a mower set to a height of 2.5 to 3 inches works well for mulching leaves and cutting grass.

Does Lawn Mower Deck Need to be Level?

Yes, the mower deck needs to be level. A lawn mower deck should have a pitch or height difference of 1/8-inch to 1/2-inch between the back and front deck heights and less than 1/8-inch between the side deck heights.

Why is it Necessary to Have a Level Mower Deck?

Lawn mowers with level blade decks cut the grass more consistently while protecting the engine and the operator. In addition to that, it safeguards the blades of the mower as well as the grass clippings.

How Often Should I Level My Mower Deck?

After using your lawn mower over rough terrain, such as curbs, you will need to ensure that the mower deck is levelled once or twice every season, or more often if required.

Final Verdict

The troubleshooting of lawn mower deck not level is not very difficult. You may simply do it in your garage. However, to avoid any problems while troubleshooting, thoroughly read the article and follow the instructions carefully.

Such problems might have been caused by a lack of operating ability or by neglect. However, before you begin, check to see that you are not using your lawn mower incorrectly.

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