Should Trailer Hub Grease Seals Be Driven Flush With Hub Bore

Updated 10/25/2024 | Published 03/09/2020

Question:

Hello, I am in the process of putting back together a new bear kit and I have a question on the grease seal and how to put this back in. Part DBRKHW35EZ. I have attached a picture for reference. On a previous question you answered, you provided a video that showed the process of putting everything back together. In the video provided, the person essentially puts the double lip grease sealinch in as far as it would go, before it stops and cant got in further least that is how I see it. On my trailer, both of the old seals are only flush with the hub as seen in the photo attached, so I am not sure if my old grease seals were coming out and were lose over time, or if for my specific trailer, that is how they are supposed to be? With the seal only flush, this clearly allowed the old bearing to move back and forth a bit while it was turning, if that makes sense, as it was not tightly in place. The inner bearing had some wiggle room. Please advise on if I should follow the video, and get the seal in as deep as it will go, or if I should keep it flush, as it was when i removed the old seals. Thanks!

asked by: Kevin

Expert Reply:

Grease seals such as those included with the # DBRKHW35EZ bearing kit should be be installed so that they are flush with the hub bore. If the correct seal is used, everything should fit together perfectly. As long as the castle nut is correctly ran down, everything should be held together well so there should be no lateral movement of the bearing. Running the castle nut isn't an intuitive process. It needs to be snug enough so that the inner and outer bearings hare held into place correctly against their races but not so tight that the bind and allow heat to build up. When correctly tightened, you won't be able to rock the hub on the spindle but the wheel should spin freely, as shown in the video I've linked for you.

expert reply by: Mike L