rear bearing seal Q for those in the know

[rexaway123]

Hi there have an easy question for those in know about the Rear bearing seal on my newish trailer.
Should the black seal rotate with the hub or stay fixed on axle stub?

see below

Have the normal Alko setup with marine black seals that sit inside the metal cup with the double rim seals that is tapped into the back of hub.

noticed a few months after new that rear seals on one side leaking grease so drips down onto brake disks but on other side perfect seal....all time hubs and axle stay cool to touch even after driving for one hr.

what I noticed today when jacked up to spin wheels is that the black seal rotates with the hub around the axle on both hubs on the side where I am losing grease...but on other side of trailer the black seal stays fixed on axle and the metal cup slips around under the outer lip with the hub as it rotates?

so which is correct to be expected??

I do not think it should rotate around at all

cheers guys

[trymyluck]

The seal should be fixed to the stub and there should be a stainless insert pressed into the back of the hub that the seal contacts.

Mark

[johncar]

Yeah I always thoroughly clean both surfaces and glue mine to the axle so there is less chance of rotation. The integrity of those seals is what is between you getting home OK or stuck on the side of the road somewhere, so worth taking the little extra care when installing them....
Just as well you noticed them at this stage.