What is Torque Spec for Castle Nut of Dexter 3,500 lb Axle

Updated 08/25/2026 | Published 08/21/2026

Question:

Dexter Trailer Axle Beam with EZ-Lube Spindles - 89 Long - 3,500 lbs Part Number: T3584F-EZ-8974 Installing new galvanized hubs on this axle. Watching your new bearing installation, it instructs to torque the castle nut to the axle specifications to seat the bearings, and then back off the axle nut. The Axle above is what I have, do you have the torque specs for seating the bearings? I know the axle nut will be just hand tight, but appears I need to seat those bearings first, then back the nut off. Thanks.

asked by: Greg K

Expert Reply:

Hey Greg, welcome back! So this is a great question but for a Dexter 3,500-lb axle, the castle/spindle nut does not stay torqued to a specific ft-lb value. Dexter's official bearing-adjustment procedure is while rotating the hub, tighten the spindle nut to approximately 50 ft-lbs. This seats the bearings. Stop rotating the hub and loosen the nut until the torque is removed. Turn the nut clockwise again until it is finger tight. For a castle nut/cotter-pin setup, back the nut off slightly until the first castellation aligns with the cotter-pin hole.
Install the cotter pin. The finished nut should have a small amount of freedom rather than putting preload on the bearings.

So 50 ft-lbs is only the initial bearing-seating torque and not the final castle-nut torque.

expert reply by: Jameson C

Randy L.

8/25/2026

Jameson is dead on. I did not use a torque wrench but did spin the hub while tightening the nut to seat the bearing. This gives an even pressure on the bearing while it is being seated.