▎What are equalizer and axle pin？
Conventional trailer suspension structures are mostly leaf springs, airbag suspensions, and a rare rubber suspension. In terms of economy and load-bearing capacity, leaf spring suspensions are of course more advantageous，the equalizer and axle pin are part of the leaf spring suspension structure. Next, we will introduce their functions and damage symptoms respectively.
Equalizer：Trailer equalizer,Located in the middle of the front and rear sets of leaf springs, it works like a "seesaw". While serving as a fixing point for the steel plate floating frame, it also balances the load-bearing capacity between the axles, allowing the force on each axle to be more evenly distributed when the vehicle is driving on uneven roads.
Generally, the equalizer is not easily damaged. Many times, it is because the load is too heavy, which causes the steel plate floating frame and the top of the equalizer to be worn too seriously, and all the force is applied to the axle pin. This axle pin acts like a "traction pin", connecting the steel plate bracket and the equalizer together.
Common equalizer damage occurs on heavy-loaded vehicles, with cracks appearing directly at the weld points on the top of the equalizer. After all, this is a fixed component of the chassis structure and has been welded when the trailer leaves the factory. If it is a standard-loaded vehicle, it is almost lifetime-free and only requires the axle pins and bearing holes to be welded and replaced.
Axle pin: In fact, from a structural point of view, the axle pin and the equalizer should be integrated into one. The reason why they are introduced separately here is that you need to pay attention when replacing them. If the base of the equalizer is not too severely worn and the bearing hole cannot be repaired by welding, you only need to replace the axle pin. Its appearance looks like a round shaft.
During operation, the axle pin combines and limits the activity range of the equalizer and the steel plate floating frame. Even if it is a cylinder, I believe everyone has heard the saying, " With hard work, even an iron pestle can be ground into a needle." If it is not maintained or replaced for a long time, the axle pin will lose its roundness due to wear and tear, thereby losing its balancing function.
▎Replacement cost and maintenance cycle
The reason why some drivers prefer leaf spring suspension is precisely because of its good load-bearing capacity and cheap maintenance. Compared with the airbag bridge, it is more suitable for transporting heavy goods and rough goods. On the contrary, the airbag bridge is only useful for green access, express delivery, and daily necessities transportation. The two target different types of goods.
The inspection and replacement cycle of the equalizer bearing holes and axle pins of ordinary leaf spring suspension depends on the driving conditions and mileage. The trailer in the picture above was worn out like this after only two years of use by the original owner. It cannot be confirmed that it is consistent with the 30,000 kilometers stated by the original owner. Of course, if the road conditions it was originally used on were too bad and the steel plates creaked due to the bumps all day, that would be another story.
If it is standard load transportation, with expressway conditions as the main condition and national road conditions as the auxiliary condition, and the round-trip heavy load is about 34-35 tons, then the maintenance cycle of the axle pin is about 10,000 kilometers, and it needs to be lubricated with grease to allow the grease to protect the axle pin. When lubricating with grease, you can also check the gap between the axle pin and the equalizer bearing hole. If it is loose, it means that the replacement cycle has arrived.
Replace the equalizer bearing hole and axle pin as a whole in a timely manner to avoid tire wear and strong tire vibration when braking. If the trailer has ABS, it will also affect the effectiveness of the ABS.
According to the repairman, the speed of disassembling the equalizer axle pin depends on whether the rear bolt is rusted. If it is rusted, it cannot be unscrewed and can only be cut violently with gas welding. One day, the bearing hole of the trailer equalizer was severely damaged and had become out of round, so the welding bearing hole had to be replaced, which was time-consuming.
▎What are the side effects of damage to the equalizer bearing hole and axle pin?
Some trailer drivers will remove and unplug the ABS of the original vehicle, and then install it back when it passes the inspection. This will directly lead to a decrease in the braking force of the vehicle, especially when the equalizer bearing hole and the axle pin are abnormally worn.
The first thing that comes with it is the different load-bearing capacities of the axles. When you cannot associate the braking system with the suspension system, it is their "lack of coordination that leads to the failure". When an ordinary three-axle trailer is empty or loaded, the load distribution on the three axles is uneven. When the vehicle brakes, the wheels with smaller load-bearing capacity will be more likely to lock.
When the vehicle is decelerating in an emergency, the wheels of the trailer will lock and there will be crazy bouncing. Even if the brakes are adjusted to be consistent on the three axles, it will be useless because there will always be an axle with uneven braking force, which will easily wear the tires and reduce the braking force. It may even directly cause the performance of the four-channel ABS anti-lock braking system to lose control. The principle is that when the wheels with small load-bearing capacity are locked, the other wheels that are not locked will be misjudged by the ABS system and the braking force will be actively reduced, which will eventually lead to a significant extension of the emergency braking distance of the entire vehicle, which is particularly dangerous in rainy, foggy, icy and snowy weather.
Therefore, when the wheels experience the above-mentioned tire wear, abnormal locking, and ABS anti-lock braking system performance failure, conduct a thorough inspection of the equalizer bearing holes, axle pins, and steel plate floating frames on the suspension structure. Based on the actual operating conditions, appropriately shorten the grease and overall replacement cycle to prevent excessive wear of the trailer suspension structure.
▎Summary
The vehicle is made up of countless precision components, and the failure of any single part can lead to the vehicle being immobilized and unable to operate, So when purchasing trailer parts, please look for the excellent quality parts produced by TND Co., Ltd,Owning a car involves more than just knowing how to drive, it also requires proper maintenance and regular inspections. By identifying and repairing issues early, you can prevent minor problems from escalating into major damage, thus maximizing profits in a low-margin environment.
