Trailer hub oil bath caps advice

 Good day guys and girls,


I have the oil bath caps on my trailer hubs and if I fill them about halfway full the oil is all gone within a very short distance - less than 50 kms. It definitely comes out the back seal. I am wondering if this is standard or is the oil meant to stay in there much longer than that?

In saying that though, the bearrings are still very smooth and don't seem to get water inside them at all. This is my first boat trailer with this design so any advice would be very much appreciated.



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Walfootrot's picture

Posts: 1349

Date Joined: 23/07/12

 Have never had or used them,

Fri, 2018-01-05 17:04

 Have never had or used them, but they should not leak... IMO


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ranmar850's picture

Posts: 2072

Date Joined: 12/08/12

No, they are not meant to leak

Fri, 2018-01-05 17:14

 They are a good idea in have just found one problem, and the other is having the cap dislodge while travelling. With normal, greased hubs, losing the cap is no real biggy if you pick up on it in a reasonable time. might mean getting all the dusty grease out later. . With the oil-filled type, you will trash your bearing pretty quickly if you expose them and lose the oil. 

Posts: 78

Date Joined: 07/12/13

Seal is stuffed or wrong seals

Fri, 2018-01-05 17:19

 The oil should remain in the hub. It should not come out.

You need to replace the seal in the rear of the hub(s). Ensure the axle is clean and smooth where the seal runs. It should almost be a polished surface or you will get leaks. 

There are two different types of seal so I found out. Choose the wrong one and the oil will be on your driveway in the morning. 


RohanKok's picture

Posts: 36

Date Joined: 25/06/17


Sat, 2018-01-06 06:52

 Thanks for the info guys! As I suspected. Guess I am getting the seals replaced then.


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squidvicious1's picture

Posts: 628

Date Joined: 22/07/10

 The hubs should come with

Sat, 2018-01-06 09:02

 The hubs should come with their own oil,heavy viscosity.

gruntre69's picture

Posts: 510

Date Joined: 15/10/16

 Make sure the not running

Sat, 2018-01-06 09:52

 Make sure the not running surface of the seal is glued in place with sika or silicon. Allow to set before running the trailer. 


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