How to Measure Trailer Spindle on Axle to Identify Correct Grease Seal

Question:

Have a 1996 prestige single axle boat trailer. Inner bearing is part #25580, inner race part # 25520. Was told original grease seal #AD7131Eo was the correct part number, I cannot verify because grease seal is burnt beyond belief. If you could provide the correct part number I would like to move forward with ordering 2 Thanks

asked by: ETHAN A

Expert Reply:

The inner bearing # 25580 is found on axles rated from 5200 to 7000-lbs and there are two grease seals commonly used with it. Both seals share the same outer diameter of 3.376-inches to match the hub's bore but they will have either of two different inner diameters, either 2.125-inches or 2.250-inches. Based on my research it appears your seal part has the smaller inner diameter so you can use grease seal part # GS-2125DL. Part # GS-2250DL has the larger inner diameter.

If you want to measure to confirm which you need simply measure your spindle at the point where the seal rides. You can refer to the linked diagram to see this point on the spindle, labelled as "B". An accurate measurement requires using a precision caliper that can measure to the nearest thousandth of an inch (That is three decimal places).

expert reply by: Adam R