January 1, 2015

How to replace a cutting blade on a zero-turn riding mower

By Lyle Weischwill
How to replace a cutting blade on a zero-turn riding mower

This step-by-step repair guide explains how to replace a cutting blade on a zero-turn riding mower. Worn or damaged blades won’t cut the grass well, giving an uneven cut and tattering the tips of the grass. Inspect your mower blades regularly and, if needed, replace a damaged cutting blade with a manufacturer-approved replacement part, using the steps in this guide.

Use this basic procedure to replace cutting blades in Craftsman, Husqvarna, Toro, MTD, and Cub Cadet zero-turn riding mowers.

Quick links
Tools required
Torque wrench
Socket wrench set
4X4 block of wood
Repair difficulty
Time required
30 minutes or less
Repair difficulty
Time required
30 minutes or less
Replacing a cutting blade on a zero-turn riding mower

This video explains how to replace the blade on a zero-turn riding mower.

Instructions

  1. 01.

    Disconnect the spark plugs

    Disconnect the spark plug wires.

    Disconnect the spark plugs.

    Disconnect the spark plugs.

  2. 02.

    Release the blade belt

    Lower the mower deck to the lowest cutting position.

    Remove the left pulley cover on the mower deck.

    Push the blade belt idler pulley in and roll the blade drive belt off the left blade pulley.

    Reach under the rear of the mower frame and remove the blade drive belt from the electric clutch.

    Lower the mower deck.

    Lower the mower deck.

    Remove the pulley cover.

    Remove the pulley cover.

    Roll the blade belt off of the pulley.

    Roll the blade belt off of the pulley.

    Release the blade belt from the electric clutch.

    Release the blade belt from the electric clutch.

  3. 03.

    Remove the mower deck

    Disconnect the mower deck mounting pins and release the hanging brackets from the mower deck.

    Push the mower deck slightly forward and release it from the front bracket.

    Pull the mower deck out from under the mower frame.

    Remove the deck mounting pin.

    Remove the deck mounting pin.

    Remove the washer.

    Remove the washer.

    Release the hanging bracket from the mower deck.

    Release the hanging bracket from the mower deck.

    Release the front bracket.

    Release the front bracket.

    Pull the mower deck out.

    Pull the mower deck out.

  4. 04.

    Remove the cutting blade

    Flip the mower deck upside down to access the mower blade.

    Wedge a block of wood between the cutting blade and the deck to keep the blade from turning.

    Remove the cutting blade mounting bolt and pull the cutting blade off.

    Tip: Turn the blade mounting bolt counterclockwise to remove it.
    Warning: The cutting blades are sharp. Wear work gloves to protect your hands.
    Flip the mower deck over.

    Flip the mower deck over.

    Remove the blade mounting bolt.

    Remove the blade mounting bolt.

    Remove the blade.

    Remove the blade.

  5. 05.

    Install the new cutting blade

    Position the new cutting blade on the shaft and install the mounting bolt.

    Tighten the bolt to 50 ft-lbs with a torque wrench.

    Tip: If blade is marked with directions such as “This side up,” position the blade as marked.
    Install the new blade.

    Install the new blade.

    Tighten the blade bolt.

    Tighten the blade bolt.

  6. 06.

    Reinstall the mower deck

    Flip the mower deck right side up.

    Push the mower deck under the mower frame.

    Reinstall the mower deck on the front bracket.

    Reinstall the mower deck hanging brackets and secure them with the mounting pins.

    Push the mower deck in.

    Push the mower deck in.

    Reconnect the front bracket.

    Reconnect the front bracket.

    Reinstall the deck hanging brackets.

    Reinstall the deck hanging brackets.

  7. 07.

    Reattach the blade belt

    Reinstall the blade drive belt onto the electric clutch.

    Push in the blade belt idler pulley and roll the blade belt back onto the left blade pulley.

    Reinstall the pulley cover.

    Tip: Make sure that the blade belt is routed correctly when reinstalling the mower deck.
    Reinstall the belt on the electric clutch.

    Reinstall the belt on the electric clutch.

    Roll the belt on the pulley.

    Roll the belt on the pulley.

    Reinstall the pulley cover.

    Reinstall the pulley cover.

  8. 08.

    Reconnect spark plugs

    Reconnect the wires on the spark plugs.

    Reconnect the spark plugs.

    Reconnect the spark plugs.

Warning: Undertaking repairs to appliances can be hazardous. Use the proper tools and safety equipment noted in the guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs should only be performed by a qualified technician.

Symptoms common to all riding mowers & tractors

Choose a symptom to see related riding mower and lawn tractor repairs.

Main causes: dead battery, stale fuel, bad starter solenoid, ignition system problem, bad ignition interlock switch, clogged carburetor
Main causes: damaged cutting blade, worn deck pulley, damaged mandrel pulley, loose fasteners on mower deck components
Main causes: shift lever needs adjustment, neutral control needs adjustment
Main causes: engine overfilled with oil, leaky head gasket or sump gasket, damaged carburetor seals, cracked fuel pump, broken fuel line
Main causes: punctured tire or inner tube, leaky valve stem, damaged wheel rim
Main causes: worn or broken ground drive belt, bad seat switch, transaxle freewheel control engaged, transaxle failure, dirty carburetor
Main causes: unlevel mower deck, dull or damaged cutting blades, worn mandrel pulleys, bent mower deck, engine needs tune up
Main causes: worn or broken blade belt, broken belt idler pulley, blade clutch cable failure, bad PTO switch, damaged mandrel pulleys
Main causes: clogged carburetor, damaged flywheel key, dirty spark plug, stale fuel, improper valve lash, engine needs a tune up

Repair guides common to all riding mowers & tractors

These step-by-step repair guides will help you safely fix what’s broken on your riding mower or lawn tractor.

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Get your mower running smoothly again by replacing the air filter—it's a quick job you can do yourself, following these steps.

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If you hear the solenoid click but don’t hear the starter motor spin when you turn the key, follow these steps to replace it.

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January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower blade

If a blade on your mower is dull or bent, replace it following the steps in this repair guide.

Repair difficulty
Time required
 30 minutes or less

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