Why Doesn't Hub Saver Have Flat to Lock onto Spindle Like Spindle Washer

Published 08/11/2026

Question:

An interesting choice of axles to use for demonstration... Deleting the brake and installing only an idler type hub. I wonder why the Hub Saver doesnt have the flat on the inside to prevent spinning on the axle, as the original washer does?

asked by: Alan S

Expert Reply:

Hey Alan, this is a great question but he Hub Saver Washer # HS69FR is designed differently than the original spindle washer, so it does not need the keyed flat that keeps the OEM washer from rotating.

The HS69FR is a retention device, not a spindle washer. Once it's installed and the spindle nut is torqued to specification, the clamping force between the washer, hub, and nut keeps it from rotating with the spindle. Its job is to help retain the hub on the spindle in the unlikely event of a bearing failure, it is not intended to prevent spindle rotation during normal operation. What axle capacity do you have?

The choice of idler hub over brake hub for the video was just for demonstration purposes.

expert reply by: Jameson C