(3) Mower Blades for John Deere D140 D150 D155 D160 Replaces GX21784 GY20852

What It Is

This is a set of three replacement mower blades designed for select John Deere lawn tractors with 42-inch or 48-inch decks. They’re meant for cutting grass on residential properties and directly replace OEM part numbers GX21784 and GY20852.

Fitment & Compatibility

Before buying, confirm your deck size: these blades fit John Deere models D140, D150, D155, and D160, but only with 42-inch or 48-inch decks. Measure your current blade length (should be about 20.5 inches) and check the center hole diameter (typically 5/8-inch) and offset. Verify your model’s deck size by looking at the sticker under the seat or on the deck itself. Aftermarket blades are not identical to OEM, so compare the thickness and shape—some aftermarket options are thinner or have slightly different lift angles. If your mower uses a different blade length or hole size, these won’t fit.

Key Things to Buy

• Quality check: Aftermarket blades may be thinner than OEM, which can bend more easily on rocks or roots. Inspect for warping after first use.
• Installation: Relatively straightforward—jack up the mower, remove the deck, and use a socket wrench. Torque bolts to 50-60 ft-lbs. No special tools needed beyond a blade removal tool or block of wood.
• Common gotchas: Always sharpen new blades before use—they often come dull. Replace all three at once for balanced cutting. Reuse the original bolts unless they’re damaged.
• Deck compatibility: Double-check your deck model (e.g., Accel Deep Deck vs. standard). These blades are not for 54-inch decks or older D-series models with different spindle spacing.

Should You Buy It

If you need a budget-friendly set of three blades for a John Deere D140-D160 with a 42-inch or 48-inch deck, and you’re comfortable with aftermarket quality, this is a solid value. It’s best for homeowners who mow weekly and aren’t hitting heavy debris—if you mow rough terrain or want maximum durability, stick with OEM blades.