A vibration that appears at a steady speed
You're driving at a constant speed between 50 and 90 km/h and you notice a vibration, as though the car is running over a rumble strip. It disappears when you accelerate firmly or slow down. On a torque-converter automatic, this symptom has a very characteristic cause.
Likely causes
| Gearbox type | Most likely cause |
|---|---|
| Torque-converter automatic | Torque converter lock-up clutch shuddering, degraded fluid |
| Dual-clutch (DSG, EDC) | Dual-mass flywheel or clutches |
| All types | Wheel balancing, driveshafts, engine mounts |
The torque converter lock-up clutch mechanically couples the engine and gearbox at a steady speed to save fuel. When its lining or the fluid deteriorates, it engages with a shudder — and that's the vibration you feel.
Rule out the simple causes first: a poorly balanced wheel or a worn driveshaft will also vibrate at these speeds, but that vibration won't disappear when you accelerate.Can you keep driving?
Yes, it's not an emergency. However, a shuddering lock-up clutch wears its lining and contaminates the fluid, which accelerates wear throughout the rest of the gearbox.
Repair or replace?
On a torque-converter gearbox, a full fluid change using the recommended fluid is sometimes enough to eliminate the shudder. If the vibration persists, the converter or the gearbox itself is at fault: a reconditioned automatic gearbox, tested and warranted for up to 24 months, avoids a cycle of repeated repairs.
