Is A Spindle Washer Needed To Go Between The Outer Bearing And Castle Nut

Updated 01/27/2026 | Published 08/17/2024

Products Featured in This Question

Dexter Hydraulic Trailer Brakes - Free Backing - 10" - Left/Right - 3,750 lbs

(151)

$186.71

Cotter Pin - 1/8" Thick x 1-3/4" Long

(893)

$1.45

Washer For 1" Spindle

(346)

$5.39

Question:

Im getting ready to replace bearings on a boat trailer with a Dexter hub 10x2-1/4 stamped with 8-247. I removed the castle nut and found there was no washer between it and the outer bearing. This was true for both left and right side. Shouldnt there be a washer? That said there was the correct space for a cotter pin so a washer might keep cotter pin from being ed. Is a washer required between castle nut and outer bearing?

asked by: Mike O

Expert Reply:

Hey Mike,

The washer is there to place even pressure on the bearing so that it doesn't bind and build heat. Since it butts up to the end of the outer bearing it will help protect it from any burrs on the back of the castle nut and help hold the grease in. I would put a new washer # SW1000 in and see if you can get the hub pressed onto the spindle enough to get the cotter pin # 165649 through the spindle.

I've attached a short video below where I'll go over the installation of the Dexter 8-247 hub-drum assembly that you can watch for some tips.

expert reply by: Kevin C

Kate F.

1/27/2026

Hey Mike, how did things go after adding the new washer and cotter pin to your Dexter hub? Your update could make it easier for the next person replacing bearings on a similar trailer setup.