Will The Hub Saver HS79FR Keep The Hub In Place If The Castle Nut Comes Loose?

Updated 08/12/2026 | Published 08/11/2026

Question:

I dont see how that washer would keep the wheel and hub in place if the castle but comes loose, either by the tang breaking or the cotter pin coming out.

asked by: Bob

Expert Reply:

Hey Bob, thanks for reaching out. That's a great question, and it's a common point of confusion. The Hub Saver # HS79FR is not designed to keep the hub on the spindle if the castle nut backs off or falls off. The castle nut, washer, and cotter pin still have to be installed and functioning correctly.

What the Hub Saver is designed to do is keep the hub and wheel from sliding off the spindle if the outer bearing fails. In a normal bearing failure, the outer bearing can disintegrate and the hub can walk right off the spindle. The Hub Saver acts as a large retainer behind the washer and castle nut, giving the damaged hub something larger to bear against and helping keep the wheel attached long enough to get the trailer safely stopped.

If the cotter pin falls out, the tang washer breaks, or the castle nut comes completely off, the Hub Saver isn't intended to compensate for that failure.

What kind of trailer do you usually tow?

expert reply by: Jesse M

Hub Saver Hub and Wheel Protector - Fits 4, 5, and 6-Lug Trailers - Qty 2
(click to enlarge)

Bob

8/12/2026

Bearing failure is normally due to improper tightening, too tight or too loose, failure to grease the bearing correctly, or the hub not being seated completely when tightening the castle nut. Or reusing the weak cotter pin or tang washer. Never reuse them. The Hub Saver 'may' keep the wheel and hub from coming off if you catch it early enough. There is really no way to know unless you lift the trailer and check for looseness, or remove the dust cap. A loose or destroyed outer bearing will ruin the inner seal an possibly the inner bearing and spindle. PS, you will never hear or even feel the bad bearing while going down the highway. I use a infrared thermometer and check the hub temperatures at almost every fuel stop. If they're all close, I drive on.

Jesse M.

8/12/2026

@Bob Thanks for sharing your experience, Bob. You brought up several great points. Regular bearing maintenance and proper adjustment are still the best way to prevent a failure in the first place. The Hub Saver isn't a replacement for that maintenance, it's an extra layer of protection if an outer bearing does fail. I like your idea of checking hub temperatures with an infrared thermometer at fuel stops too. That's a simple habit that can catch a problem before it turns into a roadside repair.