GY20684 GY20686 (3X) Mulching Blades 18-5/8" Fits John Deere 54" Cut Mower Decks

What It Is

This is a set of three mulching blades (part numbers GY20684 and GY20686) designed for John Deere 54-inch cut mower decks. They replace standard lift blades to create finer clippings that decompose faster, ideal for lawns where bagging is not desired.

Fitment & Compatibility

• Deck size: Only fits John Deere 54-inch decks; does not fit 48" or 60" decks.
• Blade measurements: Each blade is 18-5/8 inches long, 2-1/4 inches wide, with a 1-inch center hole and a 0.75-inch offset. Verify these match your current blades.
• OEM vs aftermarket: Aftermarket replacement for OEM part GY20684 (center blade) and GY20686 (two outer blades). Confirm you need three blades total.
• Model check: Compatible with John Deere X300, X500, X700 series, and select 100-series tractors with 54" decks (e.g., LA145, LA165). Check your deck model number (stamped on deck housing) to be sure.

Key Things to Know

• Quality: Made from heat-treated steel; reviews note they hold an edge well but may be slightly thinner than OEM blades.
• Installation difficulty: Moderate; requires lifting the deck or removing blades with a socket wrench. Torque bolts to 70-90 ft-lbs. Use a blade removal tool for safety.
• Common gotcha: These are mulching blades only—not suitable for bagging or side discharge unless you swap back. They create more lift than standard blades, which can strain the engine on thick, wet grass.
• Balance: Always balance new blades after installation to avoid vibration and deck damage.

Should You Buy It

Yes, if you own a John Deere with a 54" deck and want to mulch without bagging, this set offers good value versus OEM. Skip it if you need standard lift blades for bagging or side discharge, or if your deck is a different size.