It is not a daunting challenge to understand that your trailer wheels may be wobbly. It is also relatively simple to find out if your tyres are worn out. The real challenges lie in inspecting trailer wheels and tyres when you know they are not alright but you are unable to figure out what has actually gone wrong. There are times when tyres lose air pressure. This may be a seasonal thing. Air pressure does respond differently to heat, cold and humidity. What kind of terrain you are towing the trailer on will also have a bearing. Sudden drops in air pressure are concerning. More concerning is a scenario when you cannot really explain the drop in air pressure.
There are some standard inspections you can carry out to find out if your trailer wheels and tyres need replacement. For instance, the loss of air pressure may not have anything to do with the tyre and instead it could be the tube. Now you may or may not be able to access the tube if you do not know how to pull it out of the tyre. Similarly, wobbly wheels are not always a result of loosened nuts and bolts. You can always tighten them and see if they are still wobbly. The problem could be alignment. The actual problem could be the structural integrity of the wheel, including its shape. This is quite complicated to understand and only the experts would find it easy to spot and recommend accordingly.
Many trailer parts may look fine when you check them at your garage or by the road. A closer inspection may not reveal anything. The real problem may become obvious only when you uninstall the trailer parts. At times a substantial disassembling of trailer parts is required. You may have to remove the trailer wheels and tyres and test them separately to know if they are the real problems or if they are merely responding to another issue. Since trailer wheels and tyres are substantial investments, you should not readily opt for spares when you have some teething problems. You should have the wheels and tyres inspected by a professional. You can tow the trailer to the shop of a trusted technician or you can schedule a home call.
The original trailer wheels and tyres are easily the best and the most reliable but they too would have a lifespan. You will have to replace the trailer wheels and tyres at some point in time but be sure of the need before you invest.