If your riding lawn mower is cutting the grass unevenly, the mower deck might not be level or the tires might not have enough air. This video shows how to adjust and level the deck height of your riding mower.
For additional repair help, including common symptoms and troubleshooting tips, step-by-step riding lawn mower and tractor repair guides, and articles, check out our repair help section. In addition, find the riding mower parts you need to fix your mower.
Supplies you need
Tire pressure gauge
Compressed air supply
Hi, Wayne here from Sears PartsDirect. Today we're going to level the mower deck on a riding lawn mower.
Your lawn will end up with an uneven cut often resembling slanted steps if the mower deck isn't level. That’s because the blades will shave the grass short on the lower side of the deck and leave the grass tall on the other side.
To level the deck on your riding mower, you need a wrench set and a ruler. You also need a tire pressure gauge and air supply so you can inflate the tires evenly before checking the levelness. Wear work gloves during the procedure to protect your hands.
Park the riding mower on a level surface and set the parking brake. Raise the deck to its highest position and disengage the cutting blades. Shut off the engine and remove the key from the ignition.
Inflate all tires to their recommended pressures, so they’re at the same pressure on both sides of the mower. Uneven tire pressure on the left and right can mimic an uneven mower deck and cause an uneven cut.
Level side to side
First, we'll level the deck side to side. Position both cutting blades side to side and measure the height of each outside blade tip. The heights should be within 1/8-inch. If not, turn the lift link adjustment nut clockwise to raise the left side of the deck or counterclockwise to lower it. Each full turn adjusts the left-side deck height by about 3/16-inch.
Recheck the blade height measurements and continue to adjust the lift link adjustment nut until blade tip heights are within 1/8-inch.
Level front to back
Now that we’ve leveled the deck side to side, we'll check deck leveling from front to back. Position a cutting blade front to back and measure each blade tip height. The front blade tip should be 1/8-inch to 1/2-inch lower than the rear blade tip.
To adjust, loosen the jam nut and then turn the front link adjustment nut clockwise to raise the front of the mower deck or counterclockwise to lower it. Each full turn of the nut adjusts deck height by 1/8-inch.
Recheck the blade height measurements after adjustment and continue to adjust the front link adjustment nut until the front blade tip is 1/8-inch to 1/2 inch lower than the rear blade tip. Hold the adjustment nut with one wrench and tighten the jam nut with a second wrench.
That's it. You've just leveled your mower deck side to side and front to back. You can now get back to mowing without worrying about an uneven lawn.
I hope this video helps you out today. Check out our other videos on the Sears PartsDirect YouTube channel and subscribe to learn about new videos when we post them.
These step-by-step repair guides will help you safely fix what’s broken on your riding mower or lawn tractor.
Replace the mandrel assembly if the blade shaft vibrates or doesn't spin.
Get your mower running smoothly again by replacing the air filter—it's a quick job you can do yourself, following these steps.
Get your mower started again by replacing the ignition switch—it's a quick job you can do by following these steps.
Use the advice and tips in these articles and videos to get the most out of your riding mower or lawn tractor.
Test the ignition switch and wire harnesses to find the short.
How often and tall you mow your lawn has a big impact on its health. Check out these 3 rules.
Mower not cutting the grass evenly? Your mower deck might be the problem.