Shimano SLX FH-M665 Freehub Body

This unit is designed for 8, 9, and 10-speed Shimano HG-style cassettes. Please verify that your current rear hub is specifically the Shimano FH-M665 model, as freehub bodies are rarely cross-compatible between different hub series.

No, this is a replacement freehub body only. It does not include the axle, bearings, or mounting bolts, so you will need to reuse your existing hardware during the installation.

You likely need a replacement if you notice excessive play or 'wobble' in your cassette, skipping under load, or if the freehub mechanism is failing to engage properly when you pedal. If you feel grinding or resistance when spinning the wheel freely, it is often a sign that the internal bearings or pawls are worn out.

Replacing a freehub body is a moderate task that requires specific tools, including a large hex key (usually 10mm or 14mm) to remove the mounting bolt from the drive side. If you are comfortable removing your cassette and axle, you should be able to manage this, but we recommend consulting your hub's specific service manual for torque specifications.

This component is constructed from steel. This ensures durability and prevents the cassette cogs from digging into the splines, which is a common issue with lighter aluminum freehub bodies.