the blade on my ryobi 40v won't spin by hand even with battery out, feels totally locked up.

Diagnosis

The Ryobi RY401018 utilizes a direct-drive brushless motor system where the blade is mounted directly to the motor shaft. When the blade is completely locked—even with the battery removed—it indicates a mechanical seizure rather than an electrical failure. This is most commonly caused by "impact jamming," where the blade strikes a dense object (like a limestone rock or a thick hardwood root) with enough force to deform the motor shaft or wedge the blade adapter against the mower deck's internal housing. In many cases, the blade has been forced upward or sideways, causing the blade's center hub or the mounting bolt to jam against the motor's planetary gear assembly or the motor housing itself. If the blade is physically bent, it may be wedged against the underside of the deck's plastic shroud. To confirm, inspect the underside of the deck for any signs of plastic deformation or metal scraping around the blade's rotation arc. If the blade doesn't budge a fraction of an inch, the jam is likely located at the interface between the blade adapter and the motor shaft.

How to Fix It

To resolve a locked blade on the RY401018, you must isolate the blade from the motor to determine if the seizure is in the blade assembly or the motor internals.

1. Safety Prep: Ensure the 40V battery is completely removed and the safety key is pulled. Tip the mower on its side, ensuring the battery compartment is facing UP to avoid oil leaks or electrical shorts.
2. Clear Debris: Use a putty knife or screwdriver to clear all packed grass and mud from the blade area. Debris packed into the "bell" of the motor housing can create enough friction to simulate a lock.
3. Loosen the Blade Bolt: Use a 1/2-inch or 13mm socket (depending on the specific production run) and a long-handled breaker bar. The blade bolt on the RY401018 is torqued heavily; if it won't budge, use a rubber mallet to strike the head of the bolt sharply to break the surface tension.
4. Remove the Blade: Unscrew the bolt completely and lift the blade straight off the shaft. If the blade is wedged, you may need to gently pry it away from the deck using a flat-head screwdriver.
5. Test the Shaft: With the blade removed, attempt to rotate the silver motor shaft by hand. If the shaft now spins freely, the issue was a jammed blade or a bent blade adapter. If the shaft is still locked, the internal brushless motor bearings have collapsed or the internal gear has sheared.
6. Reinstallation: If the shaft spins, install a new, balanced blade. Tighten the bolt firmly, but do not over-torque to the point of stripping the threads in the motor housing.

If That Didn't Work

• Check for "Deck Wrap": Inspect the area where the motor meets the deck. Sometimes a thick piece of twine or heavy wire wraps around the shaft *above* the blade adapter, pulling the shaft tight against the housing. Use needle-nose pliers to pull out any hidden debris from the motor vent gaps.
• Inspect the Blade Adapter: If the blade is off but the shaft is still locked, check if the blade adapter (the part that slides over the shaft) is skewed. If the adapter is bent, it can lock the motor. Try removing the adapter if your specific sub-model allows, or use a penetrating lubricant like PB Blaster on the shaft interface.
• Internal Gear Failure: If the shaft remains locked after removing the blade and adapter, the internal planetary gear system has likely failed. This requires a full motor assembly replacement. You will need to remove the deck bolts and swap the entire motor housing unit.
• Shaft Deformation: Check the shaft for a visible "bend." If the shaft is bent even by a few degrees, it will bind against the motor's internal magnets. This is not repairable and requires a motor replacement.

Heads Up

• Avoid Tipping Upside Down: Always tip the mower with the battery compartment facing up. Tipping it with the motor facing up can cause debris to fall into the motor vents or lead to internal sensor misalignment.
• Blade Balancing: Never sharpen your blade with a grinder without using a blade balancer. An unbalanced blade causes vibration that can wear out the motor bearings prematurely, leading to the exact seizure you are experiencing.
• Debris Management: Avoid mowing "wet-heavy" grass. The RY401018's brushless motor is powerful, but wet clippings can pack into the motor housing, creating a concrete-like substance that locks the shaft over time.
• Bolt Torque: Always check the blade bolt tightness after the first 5 hours of use and then once a month. A loose bolt can cause the blade to wobble, which damages the motor shaft and leads to mechanical failure.