How to Determine Replacement Hubs, Grease Seals, Races, and Bearings for a Boat Trailer

Published 05/26/2022

Question:

I have a 2004 Ranger 175 VS boat and am looking at getting replacement parts for the trailer. Can someone help me locate the correct size hub seals, bearing, hub, and bearing hub cap trying to switch from oil hub to grease, i.e. bearing buddy w/ zerk fitting?

asked by: Sary C

Expert Reply:

In order to determine what replacement grease seals, races, bearings, and hubs you need, you first need to identify the capacity of your axle.

The first thing you need to do is look for any axle tag or etched axle number on the crosstube itself. Sometimes this information is inside the axle hubs if the axles came as a complete assembly. The axle information can also be found on any paperwork you received from your trailer.

If you cannot find any of the identifying information, the next method is to determine the inner/outer bearing number or determining the inner/outer bearing diameters. I went ahead and attached an image that shows how to measure the inner and outer bearings and where the bearings are located on your axles' spindles. I recommend using calipers for making this measurement like the # PTW80157 because the measurements need to be extremely precise.

After you discover the bearing numbers and/or the bearing diameters, you can then match that information with the axle chart (see attached) to determine the axle capacity. Once you know the capacity, that is when we have a solid direction about what replacement grease seals, races, bearings, and hubs you need.

As far as the Bearing Buddies, you need to measure your hub's bore. To do this, you remove the grease cap and measure the opening of the bore. I also recommend using the # PTW80157 to complete the bore measurement as well. Once you get this measurement, you will know exactly what Bearing Buddies to use.

Feel free to respond to this answer with any measurements or info you come across.