When we are doing maintenance on the trailer, we may check out some small problems. It may cost a lot of money to go to a professional repair station to adjust. So can we adjust these problems ourselves? The answer is yes.
Some small problems on the trailer can be adjusted by yourself on the premise of ensuring safety. For example, the wheels of the semi-trailer cannot run as smoothly as before. This is most likely caused by worn trailer wheel bearings.
After determining that it is the wheel bearings of the trailer that cause the unstable driving, we only need to replace trailer wheel bearings to solve the problem. So, how to change wheel bearings on a trailer? This article will explain the detailed steps.
We divide the steps of “replacing trailer wheel bearings” into two parts: remove the wheel hub and old bearings of the semi-trailer, and install new bearings.
Remove the Trailer’s Hubs and Old Bearings
Step 1 – Remove the Old Hub
First, before removing the old bearing, the tire attached to it needs to be removed, exposing the inner hub. Then use a jack to jack up the trailer to ensure safety and facilitate operation.
Step 2 – Remove the Dust Cover
Then we need a flathead screwdriver or a metal hook. Insert a screwdriver into the gap in the dust cover and pry it off. Or use a hook to pull it out forcefully (the dust cover is a metal circular cover, located in the center of the hub, to protect the bearing nuts in it, to play a waterproof and dustproof role, and to avoid rust and corrosion).
Step 3 – Pull out the Cotter Pin
The adjusting nut is fixed by a cotter pin. Before loosening the adjusting nut, the cotter pin needs to be pulled out to remove each component. (The cotter pin is a kind of metal hardware used for threaded connection and anti-loosening. It is also called a spring pin. The usage is to tighten the nut, insert it into the nut groove and the hole at the end of the bolt, and open the tail of the cotter pin to prevent the nut and the bolt. Relative rotation; when you need to pull out the cotter pin, first use pliers to straighten the opening of the cotter pin, and then pull it out)
Step 4 – Remove the Adjusting Nut and Washer
The adjusting nut and washer can then be removed. After removing the adjusting nut with a wrench, remove the washer under the nut and store it in a safe place. In order to strengthen the adjustment nut of some trailers, a reinforcement structure is installed. In this case, you can use a screwdriver to pry it off.
Step 5 – Remove the Hub Assembly
Then the hub assembly can be removed. The hub assembly includes the trailer’s hub, tire bolts and nuts. The wheel hub is installed on the axle part of the trailer, and it should be handled with care when taking it out. After carefully taking out the entire hub assembly, place it on a flat surface.
Step 6 – Take out the Outer Bearing
The outer bearing is located in the middle of the hub, towards the wheel. When taking it out, you can put your fingers into the outer bearing and pull it up. Hub bearings are divided into inner bearings and outer bearings.
Step 7 – Remove Inner Bearing from Hub Assembly
At this time, it should be noted that the installation method of the inner bearing is different from that of the outer bearing, and it is fixed by the sealing part. Removal requires tapping with a hammer and punch from the side around the bearing until the retaining part that holds the inner bearing pops out.
The above is how to remove the wheel hub and old bearing of the semi-trailer. Repeat this step for each wheel on the trailer and remove all remaining wheels. After removing the hub and bearings, the next step is to install new bearings in the hub.
Install New Bearings on the Trailer
Step 1 – Wipe off Old Lubricating Grease
Before installing new bearings, use a rag to wipe off the grease from the spindle and hub. Lubricating grease plays a role in reducing wear caused by rolling friction. But over time, the lubricating grease will become dirty and affect the lubrication effect of the parts. When cleaning the old lubricating grease, you can use kerosene or detergent to clean the bearings and hubs.
Step 2 – Apply New Lubricating Grease
After wiping clean, new lubricating grease can be applied to new bearings and hubs. Just remember to dry them completely before applying new lubricating grease. When applying new lubricating grease, lubricate the spindle fully first, which will help the next new bearing installation. Take the new bearing and grease it well with grease, including the balls inside the bearing. And apply grease to the inside of the hub.
Step 3 – Put New Trailer Bearings in Hubs and Replace with New Seals
Lay the hub flat and insert the inner bearing, putting the seal on top. Once aligned, tap lightly with a hammer until it is flush with the hub.
Step 4 – Install the Outer Bearing
Put the hub face up, lay it flat and install the outer bearing. At this point, the trailer’s new bearings have been replaced. In the end we just had to reinstall the hub assembly back on the trailer.
Step 5 – Reinstall the Hub Assembly onto the Spindle
At this time, it should be noted that in order to prevent the outer bearing from slipping off when picking up the hub assembly, you need to press it with your hands until the hub is pushed onto the main shaft.
Step 6 – Reinstall Washer and Adjusting Nut
Replace the washer in its original position, covering the outer bearing again. Reinstall the adjusting nut and tighten it with a wrench. Note: In order to prevent deviation when tightening, it should be loosened a little after each tightening until it is fully tightened.
Step 7 – Install New Cotter Pin Retaining Nuts
After confirming that the bolt has been fully adjusted, the new cotter pin can be inserted. Before reinserting, you need to loosen the nut about 1/4 turn, then pass the cotter pin through the spindle, and use pliers to bend the end of the cotter pin to lock the bolt.
Step 8 – Install a New Dust Cover
Put the dust cover back in its original position, and hit the edge with a hammer to secure the dust cover firmly.
Finally put the wheels back on the trailer, tighten the nuts with a suitable wrench, lower the jack and put the trailer back on the ground. Check whether all the tires of the trailer are installed up to standard, and make sure they are qualified and safe before going on the road.
The above is all the steps of How to Change Wheel Bearings on a Trailer, and the operation must be standardized when replacing trailer wheel bearings. Safety is no small matter!