January 01, 2015

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 riding mower 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

Video

Instructions

Tools required

Torque wrench

Socket wrench set

4X4 block of wood

Repair difficulty

Time required

15 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

01.
Disconnect the spark plugs
Disconnect the spark plug wires.
PHOTO: Disconnect the spark plugs.
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.
PHOTO: Lower the mower deck.
PHOTO: Remove the pulley cover.
PHOTO: Roll the blade belt off of the pulley.
PHOTO: Release the blade belt from the electric clutch.
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.
PHOTO: Remove the deck mounting pin.
PHOTO: Remove the washer.
PHOTO: Release the hanging bracket from the mower deck.
PHOTO: Release the front bracket.
PHOTO: Pull the mower deck out.
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.
PHOTO: Flip the mower deck over.
PHOTO: Remove the blade mounting bolt.
PHOTO: Remove the blade.
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.
PHOTO: Install the new blade.
PHOTO: Tighten the blade bolt.
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.
PHOTO: Push the mower deck in.
PHOTO: Reconnect the front bracket.
PHOTO: Reinstall the deck hanging brackets.
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.
PHOTO: Reinstall the belt on the electric clutch.
PHOTO: Roll the belt on the pulley.
PHOTO: Reinstall the pulley cover.
08.
Reconnect spark plugs
Reconnect the wires on the spark plugs.
PHOTO: 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.