How Far in a Trailer Hub Should the Grease Seal Go

Updated 08/07/2020 | Published 08/07/2014

Question:

I have a 40 ft pj trailer with 12000lb axles.. When. I put the rear seal in how for should the seal sit from The inside bearing?

asked by: David C

Helpful Expert Reply:

When installing a seal at the back of a hub the outer part of the seal will need to be flush with the hub. I have linked a video that should help. You could watch the whole video or fast forward to the 1 minute, 50 second mark to see the seal installation.

expert reply by: Michael H

Doug D.

7/29/2020

My replacement grease seals (for my boat trailer) are half the thickness (0.25") of the old one (0.437"). If I install the new grease seal in so that it is flush with the back side of the hub, I think there will be some play allowing the bearing to partially come out of the race. Can I still use these new thinner grease seals if I install them further into the hub?

Jon G.

8/7/2020

The only problem that I can see with using a seal that is thinner is the hub could potentially "scoot" back further than it's supposed to. You might want to find a middle ground because that would reduce the difference to 1/8" for both.

Doug D.

8/7/2020

@JonG Thanks for replying Jon! I will give that a try. Have a fabulous weekend!