Replacement 526921001 Blade Holder for Ryobi RY40107 Lawn Mower Model

What It Is

This is an OEM replacement blade holder (part #526921001) designed specifically for the Ryobi RY40107 40V brushless lawn mower. It secures the mower blade to the spindle and allows the blade to pivot upon impact, reducing damage to the motor and deck.

Fitment & Compatibility

• Exact model match: Only fits Ryobi RY40107. Do not use on RY40170, RY40180, or other 40V Ryobi mowers without verifying part number.
• Deck size: Compatible with the 21-inch steel deck on the RY40107.
• OEM vs aftermarket: This is an OEM Ryobi part, so it matches original specs exactly. Aftermarket holders may vary in pivot pin quality and bolt hole alignment.
• Measurements: Check that the center hole diameter is 8mm (standard for this model) and that the blade mounting bolt pattern matches your existing blade. The holder is roughly 2.5 inches across.
• What to check before buying: Remove your current blade holder and compare it side-by-side. Verify the pivot pin is not seized or bent—if the blade doesn’t swing freely, the holder is worn.

Key Things to Know

• Installation difficulty: Easy—requires a socket wrench and torque wrench. Use thread locker on the center bolt (torque to 35-40 ft-lbs).
• Common gotcha: The blade holder’s pivot pin can seize if not lubricated annually. Apply a drop of light oil to the pivot pin during installation.
• Quality: OEM plastic construction is durable but can crack if overtightened or if the blade hits a large stationary object. Inspect the holder for stress cracks before each season.
• Bundle tip: If your mower vibrates excessively, replace the blade holder and the blade together. A worn holder can cause blade wobble even with a new blade.

Should You Buy It

This is a necessary replacement if your RY40107’s blade holder is cracked, the pivot pin is frozen, or the blade won’t spin freely. It’s a direct OEM fit, so no guesswork. Skip it if your holder still pivots smoothly and you just need a blade sharpening.