Terre Products, Lawn Mower Blade Adapter, Drive Pulley Adapter, Compatible with MTD, Murray, Yard Man, Yard Machines, Remington, and More, Replacement for 687-02539

What It Is

This is a drive pulley adapter that connects the engine crankshaft to the mower deck’s blade drive system. It transfers rotational power from the engine to the blades via a belt or direct drive. Commonly used on riding mowers and tractors from MTD, Murray, Yard Man, Yard Machines, and Remington.

Fitment & Compatibility

• OEM reference: Replaces MTD part number 687-02539 (also known as 925-02539).
• Check your model number: This adapter fits many MTD-built tractors with a 1-inch diameter crankshaft and a 5/8-inch bore for the pulley. Measure your existing adapter’s shaft diameter and bore size before ordering.
• Deck size: Not deck-size specific—fit depends on the engine shaft and pulley bore, not cutting width.
• Brands: Compatible with MTD, Murray, Yard Man, Yard Machines, Remington, and other MTD-owned brands. Verify your mower’s model number against the 687-02539 cross-reference.
• OEM vs aftermarket: This is a direct replacement for the OEM part. No modifications needed if your mower originally used 687-02539.

Key Things to Know

• Quality: Solid aftermarket build at a lower price than OEM. Most users report no issues with fit or durability.
• Installation difficulty: Easy—remove the old adapter (usually held by a bolt or keyway), slide this one on, and reattach the pulley. Basic hand tools required.
• Common gotcha: The keyway slot must align with your engine’s key. If your mower uses a different key size (e.g., 1/4-inch vs 3/16-inch), this adapter may not match. Check before buying.
• Wear indicator: If your blades are slipping or the belt is riding unevenly, a worn adapter is a likely cause. Replace it before the pulley damages the crankshaft.

Should You Buy It

If your MTD-built mower uses the 687-02539 adapter and you need a reliable, budget-friendly replacement, this is a solid choice. It’s easy to install, fits as expected, and saves money over the OEM part. Avoid it only if your crankshaft or pulley bore dimensions differ from the 1-inch shaft/5/8-inch bore spec.