How often should I service my trailer wheel bearings and brakes?

The routine

• Once a year, before the season, repack every bearing with fresh seals. Do it regardless of miles. Trailers that sit for months and then do one long loaded trip are exactly the ones that need it, because grease separates and seals harden while they sit.
• Check by hand at the first stop of every trip. A hub should be warm. A hub that is hot compared with the others is telling you something.
• Inspect before any long trip, not just at the annual service.

Do it sooner when

• A hub has run hot.
• The trailer has been through deep water. A hot hub plunged into cold water pulls water past the rear seal as the air inside contracts.
• The trailer has sat for a season.
• You bought it used and do not know when it was last done.

The brakes, while the hub is off

The annual repack is the natural time to look at the brakes, because the drum is already off. Two things to look for:

• Grease or oil on the shoes or inside the drum. That means the rear seal has failed. Replace the seal and deal with the contaminated brake parts; do not just wipe and refit.
• Worn or damaged shoes and a scored drum. Electric drum brakes are sized by drum diameter and handed left and right, and a matched pair of assemblies replaces one axle. If a drum is scored or a race has spun in the hub, a greased hub-and-drum assembly is the faster repair.

Doing the job right

Replace races with bearings; they are matched sets, and a new bearing on an old race is a short-lived repair. Set the preload properly: seat, back off, finger tight, back to the nearest pin hole. Use a new cotter pin on every hub, every time, and a hubcap that actually seals.

Which kit

The axle decides the kit, not the trailer brand. A 3,500 lb axle with a 10-inch drum takes our 10-inch Timken kit; a 5,200 to 7,000 lb axle with a 12-inch drum takes the 12-inch kit. Read the numbers stamped on the old cones to be sure. Everything ships from Upland, California.