What Causes Rear Axle Noise in BMW 3 Series?

[RichardRose]

BMW 3 Series rear axle noise causes are detailed below: Improper tooth side clearance: Noise caused by improper tooth side clearance. When the preload of each bearing in the main reducer is normal, metallic impact sounds occur at the rear axle during initial vehicle movement or gear shifting for a short period. After the vehicle speed stabilizes, the impact sound turns into continuous noise. When the throttle is abruptly changed, irregular sounds appear at the rear axle, which is generally caused by excessive tooth side clearance. Bearing wear: While driving, if the noise increases with higher vehicle speed but decreases or disappears during coasting, it is usually due to bearing wear or abnormal gear clearance. If noise occurs during rapid speed changes or uphill driving, it indicates excessive gear meshing clearance.