During breaks in field operations, the two most straightforward methods—“listening for unusual sounds” and “checking temperatures”—can indeed help quickly assess bearing condition, preventing minor issues from escalating into major failures. The specific techniques are as follows:

While the machine is running, carefully listen for sounds coming from the bearing area; different noises often indicate distinct internal issues. If you hear a continuous hissing sound or a sharp grinding noise, this is typically an early warning sign, suggesting insufficient internal lubrication or the intrusion of fine dust and contaminants that are acting as abrasives to wear down the raceways. A rhythmic clicking, clacking, or other irregular noise is a more serious signal, usually indicating that the bearing’s raceways, rolling elements, or cage have suffered substantial damage, such as fatigue spalling or fracture. Additionally, if the sound is low‑pitched and grows louder with increasing speed—producing a dull rumble—it may be due to excessive bearing clearance or severe raceway wear.

During shutdown inspections—always prioritize safety by first confirming that the equipment has come to a complete stop and avoiding contact with rotating parts—you can use the back of your hand to gently feel the temperature near the bearing housing. Typically, the operating temperature of agricultural‑machine bearings should not exceed 80°C. If your hand feels uncomfortably hot and you cannot keep it there, the bearing is likely overheating. This is often caused by severe oil starvation, degraded grease, excessive clearance leading to seizure, or significant internal wear that generates substantial frictional heat. Additionally, if several bearings on the same shaft exhibit markedly different temperatures, with one significantly hotter than the others, this indicates a potential fault in that particular bearing.

Once the aforementioned abnormalities are detected by listening for unusual noises or feeling for excessive temperatures, the machine should be stopped immediately for inspection. If the issue is insufficient lubrication, promptly add the appropriate grease and check whether the abnormal sounds and temperature return to normal. If the problem stems from seal damage, internal wear, or persistent high temperatures that do not subside, the bearing must be replaced without delay. Under no circumstances should you attempt to continue operation out of complacency; doing so can easily lead to bearing seizure, shaft binding, or even damage to the entire drive shaft, wasting precious time during critical periods of harvest and planting.