Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.
Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.
Summary
An uneven mower deck cuts grass at different heights and leaves visible stripes. This procedure levels the deck side to side and front to rear using a measuring device and wrenches to adjust the suspension linkage. The deck is leveled on a flat surface with proper tire pressure. Blade tips are measured from the ground and adjusted until they are the same height on both sides and the rear is slightly higher than the front.
Necessary equipment
| Item | Note |
|---|---|
| Heavy gloves | Protect hands when handling blade tips and metal parts. |
| Measuring device | Use a ruler, measuring tape, or factory deck-leveling gauge to measure blade height. |
| Adjustable wrench or socket set | Use three-fourths inch and five-eighths inch wrench sizes. See your manual for exact fastener size. |
Specifications
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
Preparation
Disconnect the spark plug wire or battery negative cable before work.
Unexpected engine start causes hand and arm injuries.
- Disconnect the spark plug wire or battery negative cable.Report a problem with step 1, Preparation
- Park the mower on level ground.Report a problem with step 2, Preparation
- Inflate all four tires to the pressure your operator manual states.Report a problem with step 3, Preparation
- Raise the mower deck to the highest position.Report a problem with step 4, Preparation
Level side to side
Wear heavy gloves.
Blade edges are sharp and cause cuts.
- Wear heavy gloves and turn the mower blades to point left and right.Report a problem with step 1, Level side to side
Keep fingers clear of adjustment linkage nuts.
Fasteners trap skin and pinch if turned.
- Measure the distance from ground to the blade tip on the discharge side.Report a problem with step 2, Level side to side
- Measure the distance from ground to the blade tip on the opposite side.Report a problem with step 3, Level side to side
- If both measurements differ, locate the lift-link adjustment nuts on the lower side.Report a problem with step 4, Level side to side
- Turn the adjustment nuts clockwise to raise or counterclockwise to lower.Report a problem with step 5, Level side to side
- Measure both sides again and repeat until measurements match.Report a problem with step 6, Level side to side
Level front to rear
- Turn the mower blades to point forward and backward.Report a problem with step 1, Level front to rear
- Measure the distance from ground to the front blade tip.Report a problem with step 2, Level front to rear
- Measure the distance from ground to the rear blade tip.Report a problem with step 3, Level front to rear
- See your operator manual for the correct rear-to-front height difference.Report a problem with step 4, Level front to rear
- Locate the front suspension linkage nuts your manual specifies.Report a problem with step 5, Level front to rear
- Turn adjustment nuts clockwise to raise or counterclockwise to lower.Report a problem with step 6, Level front to rear
- Measure both positions again and repeat until the specification is correct.Report a problem with step 7, Level front to rear
Verification
- Turn blades to different positions and repeat the measurements.Report a problem with step 1, Verification
- Reconnect the spark plug wire or battery negative cable.Report a problem with step 2, Verification
- Lower the deck to normal height and mow a test area.Report a problem with step 3, Verification
Terminology
This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.
- mower deck
- Also called: no common alternatives
- blade tip
- Also called: no common alternatives
- side-to-side
- Also called: no common alternatives
- front-to-rear
- Also called: no common alternatives
When to use a professional
Stop work if the deck has cracks or bent linkage.
Common questions
Why does my mower leave stripes when I cut?
An unlevel deck is the most common cause of striped cutting. Different blade heights cut grass at different levels, leaving visible alternating strips of shorter and taller grass. Leveling the deck side to side and front to rear should resolve this. Other causes include dull or damaged blades, worn suspension components, or uneven lawn terrain.
How often should I level my mower deck?
Check deck level at the start of each mowing season and after any impact that might change deck position. Some manufacturers recommend checking monthly during use. Regular maintenance extends the life of both the deck and the blades.
Can I level the deck without removing the blades?
Yes. The procedure measures blade height by placing the mower on a level surface and measuring from the tip to the ground. You do not need to remove the blades, only manually position them to point in different directions for measurement.
What if I cannot get the measurements to match?
Double-check your tire pressure first, as underinflated tires can affect deck level. Ensure the mower is on a truly level surface. If adjustment fasteners are stuck, apply a penetrating oil and wait before trying again. If you still cannot achieve the specification, bent linkage or other damage may require professional service.
Related procedures
- What size blade fits my mower, and how do I check the length, center hole and mounting pattern before I buy a replacement?
- How to change the spark plug on a lawn mower
Sources
Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.
Revision history
Current version 1 · updated 2026-08-03 · next review due 2027-08-03
- v1 · 2026-08-03First publication.
Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.
Comments and corrections
Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.
Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.