Hub Motor Axle Seal

[mangosteen]

Hi All,
I just bought a 1KW MXUS XF40 DD hub motor for my first ebike build.

I noticed that the seal between the side cover and axle (on the freewheel side) is a bit messed up. It looks like around half the circumference the inner seal lip got folded to the outside of the motor. It's a bit hard to see, but it is visible on the right half of the axle in the attached image.

My question is simply whether this is something worth worrying about. If it's important I could ask about returning it, but I'd rather save everyone the hassle otherwise. The seller has offered to send a replacement seal, so I could also just try swapping it out, either immediately or if it becomes an issue. Any thoughts?

 

[amberwolf]

I'd take them up on the new seal, it should be easy enough to get the old one off and the new one on. You can use a teensy dab of dish soap on the axle to slide it on so it doens't do the same thing, or if you keep it around for cooking you can use xanthan gum and water to make a slimy water-soluble liquid to do the same job.

Vaseline/etc could also be used, but I don't know what rubber they use for the seal, and that can sometimes degrade some rubbers/plastics (as can mineral oil, etc).

The seal is there to help minimize water intrusion directly into the bearing. It won't stop it completely nor will it keep water out of the motor, but it'll help the bearing to last longer than otherwise.

If the rubber of the seal isn't vulnerable to it, you can add a bit of automotive axle grease (or other similar-consistency grease) to the visible portion of the bearing before installing the seal, to aid in water-intrusion-repulsion.

 

[mangosteen]

Thanks @amberwolf , I appreciate the suggestions. I don't anticipate using it in wet conditions, so I think I'll lubricate the seal, use the wheel, and just plan to swap the seal out later.