Parts Stop stocks the Genuine Bearing Buddy — the original trailer wheel bearing protector, in Model 1781 to suit a 1.781 inch (45.24mm) hub bore, which is the one that matches hubs running the NSK (A) bearing kit. Supplied as a pair. On the shelf, ready to go.

Here's what it does and why it matters: a hot hub backed into water contracts the air inside and creates a vacuum that sucks water and grit straight past the seals — which is how bearings die on boat and immersion trailers. The Bearing Buddy replaces the dust cap with a spring-loaded piston that holds a steady few psi on the grease, so water can't get in and the hub stays packed. The 'genuine' bit matters: it's self-regulating so it won't over-pressure and blow the seal, which is exactly where cheap copies fail. Fitting it is a tap-in job, and it turns bearing repacking from a regular chore into a rare one.