GX20249 Mulching Blades for John Deere 42'' Deck L110 L100 L105 L107 L108 L111 L118 L17.542 L1742 42Inch Lawn Tractor Replace GX20249 GX20433 GY20567 Circle Shaped 3-in-1 Mower Blades 2 Pack

What It Is

This is a 2-pack of aftermarket 42-inch mulching blades for select John Deere lawn tractors. Designed for 3-in-1 cutting (mulch, bag, side discharge), they replace OEM part numbers GX20249, GX20433, and GY20567. Best for homeowners maintaining a standard residential lawn.

Fitment & Compatibility

Before buying, confirm your deck is exactly 42 inches (measured blade tip to tip, not deck housing). These fit John Deere L100, L105, L107, L108, L110, L111, L118, L17.542, and L1742 models. Also check your current blade shape: these are circle-shaped (not star or wing-tipped). If your OEM blades are GX20249, GX20433, or GY20567, these will bolt on. Measure your center hole diameter (should be 1 inch) and ensure the drive belt and spindle are in good condition—worn spindles can cause blade wobble and poor cut quality.

Key Things to Know

• Quality vs. OEM: Aftermarket blades are typically thinner and less hardened than John Deere factory blades. They will dull faster, especially on sandy or weedy lawns.
• Installation difficulty: Easy—requires a socket wrench and torque wrench (40-50 ft-lbs). Use thread locker on bolts to prevent loosening. Lift the deck safely with jack stands; never rely on the mower’s hydraulic lift.
• Common gotcha: These blades are slightly shorter than some OEM replacements (about 1/4 inch). This can reduce overlap and leave uncut strips if your deck is worn or misleveled. Always level the deck after installation.
• Balance: Aftermarket blades often arrive unbalanced. Check with a blade balancer ($10) and file the heavy side to avoid vibration and spindle damage.

Should You Buy It

Buy these if you have a compatible John Deere 42-inch deck, want a budget-friendly blade for light residential use, and are comfortable with basic installation and balancing. Skip them if you mow thick or tall grass frequently, need maximum blade life, or prefer OEM fit and finish—spend the extra $15-20 for factory blades.