How to Level the Deck on a Riding Mower

Learning how to level a lawn mower deck is one of the keys to achieving a premium quality cut for your grass, since it helps to ensure the mower blade is at the correct distance from the ground on both sides, and that it is also positioned correctly from front to back.

You can use a measuring tool to measure how far the blade is from the ground on both sides of the deck, which should be within 1/16 inch from one side to the other.

If you find that the measurements are off, you’ll want to begin the levelling process by first checking tire pressures, following instructions on your operator’s manual, and making sure the front tire pressures are equal and inflated to the correct pressure.  

Next you may need to level the deck from side to side and also ensure the deck is adjusted to the correct pitch forward, which allows for maximum vacuum up into the deck.

The following instructions detail those steps, helping you to level the deck belt on a Troy-Bilt riding lawn mower. Depending on your model, the instructions may vary slightly. Always be sure to check your operator’s manual for detailed deck levelling instructions.

Instructions to Level a Lawn Mower Deck

1. Be sure the mower is on a flat level surface. Turn the engine off and make sure it is cool. Remove the ignition key. Disconnect the spark plug ignition wire and engage the parking brake.
2. To level the deck from the front to rear, place the deck lift lever in the middle position.
3. Wearing gloves, rotate the blade closest to the discharge chute parallel to the lawn mower.
4. Measure the height of the front blade tip to the ground. Next, measure the height of the rear blade tip to the ground. Refer to your operator’s manual for proper height differences between front and rear.
5. To raise the front of the deck, tighten the hex nut. If the front of the deck needs to be lowered, loosen the hex nut. 
6. Wearing gloves for protection, level the deck from side to side by rotating the blades perpendicular to the lawn mower.
7. Measure the height of the blade tips on each side of the deck from the ground.
8. Adjust the deck by loosening the hex bolt on the left hangar bracket.
9. Raise or lower the deck by turning the adjustment gear.
10. When both blade tips have the same measurement from the ground, tighten the hex bolt.
11. Reconnect the spark plug ignition wire.