How to Identify Correct Replacement Bearings & Seals for Single Axle Boat Trailer

Question:

I have a 2003 presitage single axle boat trailer. Im looking for a bearing kit to redo the bearings wo pulling them apart first. I do know its a tapered torsion axle. Im assuming its a 1 1/4 x 1 3/4. Just want to make sure before I purchase them. Thank you.

asked by: Joel J

Expert Reply:

You will need to pull one of your trailer hubs to confirm the bearing part numbers unless the manufacturer can look up the trailer's VIN to get that information for you. For a 14-year-old trailer they may not maintain records of such construction details. This is not unusual among trailer makers. To avoid purchasing incorrect parts you will be better off pulling one hub and removing its bearings and seal to obtain their part numbers. Then selection of new bearings and related parts is easy and virtually fool-proof.

The linked photo shows you the typical placement and appearance of bearing numbers. It also shows you the points on the spindle that will need to be measured to the nearest thousandth (such as 1.234-inches) in the event that you cannot get part numbers. Measuring requires a precision caliper; a ruler or tape measure will not be accurate enough to measure the spindle. Point B corresponds to the grease seal inner diameter; point C corresponds to the inner bearing inner diameter; and point D corresponds to the outer bearing's inner diameter. Part numbers are easiest but measurements are a good fall-back option.

I linked our main page for bearings, races, seals and also for bearing kits like # BK3-300. An article on replacing these items is also included for you.

expert reply by: Adam R