Wheel Bearing Maintenance - How to repack a trailer wheel bearing
Avoid a big repair bill by performing this simple maintenance
How many trailers have you seen on the side of the road this year with one wheel propped up? If you have RIB trailer and have not checked your wheel bearings lately, this article is for you. You can do this simple task in about an hour and save yourself a big repair bill and the grief of being stranded on a busy road.
Many trailer manufacturers recommend this maintenance every year if your trailer gets normal use. To do this job, you'll need a jack, a pair of axle stands, a large screwdriver, a hammer and needle nose pliers, clean rags, a small pan, about half a litre of paraffin and a spray can of brake cleaner.
First, loosen the lug nuts on one wheel and raise the side of the trailer with a jack. Support the trailer with axle stands and then spin the wheel and listen to the bearings. If the wheel spins freely and quietly, proceed with repacking the bearings. If you hear friction or a growling sound, you most likely have a bad bearing or spindle. If this is the case, take the trailer to a service centre to get the bearings replaced.
1. Remove the lug nuts and the wheel. Be sure that the trailer is supported with axle stands and the opposite wheel is blocked.
2. Pry the dust cap loose with a large screwdriver.
3. Straighten the ends of the cotter pin and pull it out with needle nose pliers.
4. Remove the retaining nut and washer, then pull the hub off the spindle. Be careful the bearings will come out with the hub. Set the bearings on clean newspaper.
5. To remove the rear bearing and seal, tap along the rim of the bearing with a block of wood and a hammer. If the seal is rusted to the back of the hub, spray a little WD-40 on the back to help loosen it. If the seal is damaged, replace it. Clean all the grease from the bearings, races and seal with a brush in a small pan of paraffin. Inspect them for signs of wear and replace them if they look suspect. Once the bearings and parts are clean, spray them with brake cleaner and set them aside to dry. Wipe the spindle and the inside of the hub with a clean rag to remove all the grease, and clean them with brake cleaner as well.
6. Push the grease into the bearings, working from the wide side of the bearing. Keep pushing the grease into the roller until the cage and rollers are filled. Next coat the inside of the hub with grease. Tap the seal back onto the rear of the hub with a block of wood and hammer, and install the hub and bearings back on the spindle.
7. Thread the nut back onto the spindle and turn it clockwise. Spin the hub a few times as you tighten to make sure the bearings are seating properly. Tighten the nut firmly. Now back the nut off about an eighth of a turn until the hole in the spindle aligns with a space in the nut. Push in a new cotter pin and bend the ends of the pin to keep it from working its way out. Tap the dust cap back into place. Coat the lug threads with anti-seize compound, reinstall the wheel and tighten the lug nuts. Do the same for each wheel.
Trailer Fault Finding Table
| Fault | Possible Cause | Remedy |
| Brakes overheat | Wheel brakes over adjusted | Adjust correctly |
| Wheel brake dirty/rusty | Clean and re-set | |
| Handbrake not releasing or left on | Check mechanism and adjust | |
| Bowden cable(s) kinked | Check and replace | |
| Drawtube dirty and/or bent | Clean or replace | |
| Overrun lever/brake lever Sticking and/or bent | Grease or replace | |
| Braking effort weak | Wheel brakes not adjusted | Adjust correctly |
| Brake linings glazed or contaminated | Clean or replace and re-set | |
| Incorrect clearances in system | Check and re-set | |
| Drawtube dirty and/or bent | Clean or replace | |
| Reversing difficult | Braking system set too tight | Check and re-set |
| Handbrake weak | Braking system set incorrectly | Check and re-set to eliminate excessive travel |
| Uneven or jerky braking | Too much play in braking system | Check and re-set |
| Worn damper in overrun | Replace | |
| Faulty components in wheel brake | Check and replace | |
| Ovality in drum | Check and have skimmed, or replace | |
| Wheel brakes unevenly adjusted | Check and re-set | |
| Bowden cable kinked | Check and replace | |
| Brake linings contaminated | Check and replace | |
| Excessive nose weight | Check and adjust load | |
| Banging from overrun when braking | Damper resistance completely gone | Replace. Then adjust brakes. |
| Difficulty coupling and uncoupling | Coupling head mechanism dirty or damaged | Check and clean or replace |
| Towball dirty | Clean and, if necessary, grease | |
| Towball damaged | Check and replace | |
| Excessive play between coupling head and towball | Coupling head worn | Replace |
| Towball worn | Replace | |
| Wear in back of eye and rear of pin | Jaw too wide | Check and replace eye |
| Wear on inside and outside of front of eye | Jaw too tight | Replace with wider jaw |
| Pin seized in jaw | Jaw crimped by excessive noseweight | Replace jaw and reduce noseweight |
| Stress fractures on couplings or trailer drawbar | Incorrect eye/jaw combination | Check and replace with compatible components |
| Excessive overhang on towing vehicle | Check and discuss with operator. Possibly fit Shocklink | |
| Mis-match of towing heights | Modify towball or trailer coupling position or fit height adjustable equipment |