How to Maintain and Adjust a Reel Mower

For homeowners seeking a quiet, eco-friendly, and precise cut for their lawn, a manual or powered reel mower is an excellent choice. Unlike rotary mowers that tear grass, a reel mower’s blades shear it like scissors, promoting healthier turf. To keep this system performing at its best, regular reel mower maintenance and adjustment is essential. This guide provides a focused, step-by-step walkthrough of the core tasks: sharpening the reel blades, setting the bedknife gap, and performing routine lubrication. For a broader look at mower options, see our overview of types of lawn mowers.

Why Reel Mower Maintenance Matters

A well-maintained reel mower provides a clean, healthy cut for your lawn. When the blades are sharp and properly aligned, they slice grass cleanly instead of bruising or tearing it. This helps the grass heal faster, reduces water loss, and can deter disease. Neglecting maintenance, however, leads to a ragged cut, increased pushing effort, and can permanently damage the cutting components. Regular upkeep is simpler and far less costly than major repairs or replacement. Whether you have a classic push model or a newer powered version, the principles of reel mower care are the same.

Step-by-Step Reel Mower Maintenance and Adjustment

Follow this sequence for a complete tune-up. You’ll need a few basic tools: wrenches or hex keys (as specified by your mower’s manual), a feeler gauge set, a flat file, reel mower grinding compound or fine valve lapping compound, and lubricating oil.

1. Cleaning and Inspection

Before any adjustment, thoroughly clean the mower. Tip it back (reel facing up) and use a brush and a damp cloth to remove all caked-on grass, dirt, and debris from the cutting cylinder, bedknife, and frame. This gives you a clear view of the components and prevents grit from interfering with adjustments. Inspect the blades for nicks, dents, or significant dullness. Check that all nuts and bolts are tight, and ensure the wheels and drive mechanism (if present) move freely.

2. Sharpening the Reel and Bedknife

Sharpening restores the scissor-like cutting action. The goal is to create a fine, sharp edge on both the spinning reel blades and the stationary bedknife.

• Backlapping (The Preferred Method): This is the standard technique for home maintenance. Apply a thin, even coat of reel mower grinding compound to the cutting edge of the bedknife. Then, manually rotate the reel backwards (opposite its normal cutting direction) while applying light pressure to engage the blades with the bedknife. Continue for several dozen revolutions until you see a bright, uniform wear pattern on both the reel blades and bedknife. Wipe away all compound residue completely.
• Filing: For minor touch-ups or to remove a small nick, you can carefully use a fine flat file. File the bedknife only on its top, beveled edge, maintaining its original angle. Filing the individual reel blades is a more advanced task typically requiring special tools and is often best left to a professional service.

3. Setting the Bedknife Gap

This is the most critical adjustment. The gap between the reel blades and the bedknife must be even along its entire length and set to the correct clearance—typically the thickness of a sheet of paper.

1. Consult your mower’s manual for the specified gap, often between 0.001 and 0.003 inches.
2. Loosen the bedknife adjustment bolts or screws at each end just enough so the bedknife can be moved.
3. Insert a feeler gauge of the correct thickness between a reel blade and the bedknife at one end.
4. Gently tap or adjust the bedknife until you feel a slight drag on the feeler gauge. Tighten the adjustment bolt at that end to lock it.
5. Repeat the process at the opposite end and at the center, checking that the drag is consistent. The reel should just barely kiss the feeler gauge along the entire length without lifting it.
6. Re-tighten all bedknife mounting bolts securely. Re-check the gap after tightening, as it can shift.

4. Lubrication and Final Steps

Proper lubrication reduces wear and keeps the mower operating smoothly.

• Reel Bearings/Axles: Apply a drop or two of light machine oil to the reel shaft bearings at each end of the cylinder. Rotate the reel to work the oil in.
• Drive Gears and Chain (if equipped): Lightly grease any exposed gears and apply chain lubricant to the drive chain on self-propelled models.
• Wheel Axles and Height Adjusters: A light spray of silicone lubricant on wheel axles and height-of-cut adjustment levers prevents sticking.
• Bedknife (Optional): A very light wipe of oil on the bedknife after cleaning can prevent rust.

Finally, give the reel a forward spin. It should rotate freely and you should hear a consistent, light clicking sound as the blades pass the bedknife—the sound of a proper gap. Your mower is now ready for a test cut.

Maintenance Schedule and Troubleshooting

For a typical residential lawn, a full backlap and adjustment should be done at least once per mowing season, or more often if you mow frequently or hit debris. Wipe down the mower after each use to prevent grass buildup. Lubricate moving points every few uses or as specified in your manual.

FAQ

How often should I sharpen my reel mower?

This depends on use. For an average lawn mowed weekly, a full sharpening via backlapping at the start of the season and once or twice during peak growth is usually sufficient. If you notice a decline in cut quality or increased effort, it’s time to sharpen.

Can I use sandpaper instead of grinding compound for backlapping?

We do not recommend it. Specialized reel mower grinding compound or fine valve lapping compound is formulated with an abrasive suspended in grease, which is both effective and less likely to cause uneven wear than wrapped sandpaper. Using the correct compound ensures a proper sharpening surface.

What if my reel blades touch the bedknife in one spot after adjustment?

A single point of contact indicates the reel or bedknife is bent or warped. First, double-check that the bedknife mounting surface on the mower frame is clean and free of debris. If the problem persists, the mower likely needs professional servicing to true (straighten) the reel or bedknife, which requires specialized equipment.

Is reel mower maintenance harder than rotary mower maintenance?

It’s different. Rotary mowers require less frequent blade sharpening but often involve engine maintenance (oil, air filter, spark plug). Reel mowers have no engine (or a simpler one) but demand more precise mechanical adjustment of the cutting unit. Many homeowners find the focused, mechanical nature of walk-behind mower reel maintenance to be a satisfying DIY task. For those considering a new push mower, our push mower buying guide covers both reel and rotary types.

When should I consider professional service?

Contact a professional if you have a bent reel or bedknife, severely damaged blades, worn-out bearings, or if adjustments do not resolve poor cutting performance. Professional shops have the tools to true components and perform precision grinding that is difficult to achieve at home.