- Failing or worn-out differential bearings (especially pinion bearings) can create progressively increasing noise coming from the rear end.
Gear-Related Issues:
- Uneven wear or damage to ring and pinion gears can lead to increased noise over time.
Propeller Shaft Problems:
- Issues with the propeller shaft (driveline) itself, such as worn or damaged universal joints, could develop a gradually worsening noisy condition.
Axle Or Shaft Play:
- Excessive play or looseness in components like axle bearings or the driveshaft can escalate into a progressively louder noise over time.
Transmission:
- In certain cases, a transmission problem, such as worn gears, can also cause a gradually increasing noise, which could be particularly noticeable at the rear of the vehicle if it's a rear-wheel drive model.