Which is a possible cause of a whining torque converter noise not changing with lock-up engagement?

Which is a possible cause of a whining torque converter noise not changing with lock-up engagement?

• A. Stator
• B. Wear in the converter pump drive hub bushing
• C. Both A and B
• D. Neither

Answer: (B)

A whining noise that doesn’t change when the lock‑up clutch engages points to a issue in parts that are always driven by the engine, not the lock‑up mechanism. The converter’s pump drive hub bushing supports the pump shaft; when it wears, it allows excess movement and misalignment of the pump. That wear causes abnormal pump gear mesh and bearing noise that stays audible regardless of whether the lock‑up clutch is locked, because lock‑up only affects the turbine’s connection to the input and reduces slip, not the pump’s internal clearances. If the stator or its one‑way clutch were worn, the noise would more likely vary with the torque path or engine speed and could change when lock‑up is engaged, making it less consistent with a noise that remains the same. So the wear in the converter pump drive hub bushing best explains a whining sound that doesn’t react to lock‑up.

A whining noise that doesn’t change when the lock‑up clutch engages points to a issue in parts that are always driven by the engine, not the lock‑up mechanism. The converter’s pump drive hub bushing supports the pump shaft; when it wears, it allows excess movement and misalignment of the pump. That wear causes abnormal pump gear mesh and bearing noise that stays audible regardless of whether the lock‑up clutch is locked, because lock‑up only affects the turbine’s connection to the input and reduces slip, not the pump’s internal clearances. If the stator or its one‑way clutch were worn, the noise would more likely vary with the torque path or engine speed and could change when lock‑up is engaged, making it less consistent with a noise that remains the same. So the wear in the converter pump drive hub bushing best explains a whining sound that doesn’t react to lock‑up.