How to Identify Correct Replacement Bearings and Seals for Boat Trailer

Updated 05/29/2025 | Published 08/08/2017

Products Featured in This Question

LubriMatic Deluxe Bearing Packer

(63)

$29.42

Powerbuilt Deluxe Bearing Packer

(63)

$45.96

LubriMatic Marine Trailer Wheel Bearing Grease - 3 oz. Cartridges - Qty 3

(304)

$39.62

7-Piece Installation Set for Bearings, Races, and Seals

(245)

$52.59

Question:

Hello, I am going to change the bearings on my boat trailer. What do I need to do or to provide to insure that I purchase the correct parts? Thank you.

asked by: Steven L

Helpful Expert Reply:

Replacing your boat trailer's wheel bearings and seals is easiest if you pull one of the hubs and remove the inner and outer bearings and grease seal. The part numbers for these items usually appear as shown in the linked photo, and knowing the part numbers is the surest way to know you have selected the correct replacement parts. If you cannot get the part numbers please let me know and I will give you help with how to measure the spindles and hubs for the parts' sizes.

We offer individual bearings, races and seals and also kits that include the most popular combinations. The linked page displays all such items. And the article included for you provides a table that shows the most common bearings, races and seals based on the axle's weight rating; this can usually be found on a sticker on the axle itself.

When you re-pack your bearings you will want to remove as much of the old (and potentially contaminated) grease as possible from the hub interior and spindles. This will also allow you to inspect the spindle for any signs of heat-related damage.

A bearing installation kit like # PTW83020 will make it easier to get the new parts in place; please refer to the linked video for illustration. Packing them with fresh grease is easiest if you use a packing tool such as # ALL647646. Use marine-grade wheel bearing grease like # L54FR.

expert reply by: Adam R

click to enlarge

Alvin A.

5/28/2025

I saw you offered to help someone else determine the right bearings and seals. My trailer is a Dixie Craft doble-axle for a 24-ft. pontoon. The axle configuration isn't like the illustration you give. The spindle only has one step-up that measures 1 7/32". The rest of the spindle is 1". The old seal doesn't have a number on it, but the outer bearing is marked "KOYO USA HI-CAP L44643R A-X". I would really appreciate if you can give me good numbers.

Jameson C.

5/28/2025

@AlvinA Is the step up dimension you mentioned possibly for the grease seal and not where a bearing would ride? Could you possibly get me the other bearing number as well? If so then you'd need the hub part # AKIHUB-440-2-G-1K.

Alvin A.

5/29/2025

@JamesonC Yes, the grease seal rides on that 1 7/32 (possibly 1 1/4") section. I measured the inside of the rubber part of the seal at 1 1/4" but perhaps not accurately. Also, the inner and outer bearings are the same, L44643R. Thank you for your help.