I put this Knott hub maintenance guide together because of a question we hear at the parts counter. “Do I need to grease my Knott hubs before I take the boat out?” If your trailer has Knott sealed bearings, you can skip the grease gun. I do recommend having your dealer inspect the hubs once a year, preferably before your first trip of the season.
The Knott Rock & Roll Check
Ask your trailer service dealer for a wheel play and bearing check. We call it Rock & Roll because that’s what the technician does. With the trailer secured against movement and properly supported according to its owner’s manual, the technician checks the wheel while it’s clear of the ground.
- Rock it. Hold the wheel on both sides and gently rock it to feel for looseness or play.
- Roll it. Turn the wheel by hand. It should feel smooth. Listen for rumbling or grinding, and feel for roughness as it turns.
If you feel play or roughness, or hear an unusual noise, have the dealer find the cause before you tow. If the sealed bearing has failed, replace the hub assembly.
Save this Knott hub maintenance guide with your trailer records so you can find the inspection steps before next season.
Which Cap Goes on a Knott Sealed Hub?
Use the correct dust cap and O-ring for your hub. The bearing is sealed inside the assembly. Grease pumped through a grease-fitting cap stays outside the bearing.
What I’d Check Before Installing a New Hub
Have the spindle checked before the new hub goes on. Ask the technician to look at the threads and the spot where the rear seal rides. Rust or pitting there can keep the seal from doing its job. If that surface is damaged, the axle may need service or replacement.
Use the new single-use spindle nut supplied with the kit. Follow the instructions for your axle and wheel. The spindle nut and wheel lug nuts each have their own torque specification.
Which Knott Hub Fits My Trailer?
If you call and tell me you have a five-lug Knott hub, my next question will be, “What does the axle tag say?” Both kits below use a 5 on 4½″ wheel bolt pattern. The axle tag and the markings on your old hub help us find the right one.
- AutoFlex-Knott 5-Lug Sealed Hub Kit for 1,560 lb Axle 250-033290. This page shows the red axle tag we photographed on our EZ Loader 68BT yard trailer.
- AutoFlex-Knott 5-Lug Sealed Hub Kit for 2,700 lb Axle 250-033291. Check this kit if you have a two-place PWC trailer with the matching AutoFlex-Knott torsion axle.
Still working out which style you have? See our EZ Loader Hub Identification Guide.
Call Us Before You Order
Have your trailer VIN handy. If you can, take one clear picture of the axle tag and another of the existing hub. Send them to Parts@411Marine.com or call us at 843-683-5797. We answer the phone, and we’ll help you match the hub to the trailer you have.