Hyundai ix35: A6GF1 6-Speed Auto Torque Converter Lock-Up Shudder

The A6GF1 6-speed automatic transmission fitted to the ix35 and Tucson LM exhibits torque converter clutch shudder felt as a vibration or judder in the drivetrain at steady cruise speeds between 60 and 90 km/h when the converter lock-up clutch is partially engaged. The fault is caused by degradation of the transmission fluid friction modifier additives and wear of the lock-up clutch friction material over time and mileage. Hyundai issued an updated transmission fluid specification and flush procedure as the primary remedy; persistent shudder after fluid change indicates clutch friction material damage requiring torque converter replacement.

• Vibration or judder at steady 60-90 km/h cruise speed
• Shudder disappears immediately on light acceleration or deceleration
• Sensation similar to driving over fine rumble strips
• Shudder more pronounced when transmission fluid is old or degraded
• No shudder at lower town speeds or higher highway speeds

1. 1

   Test drive at steady 60-90 km/h on flat road holding constant throttle.

2. 2

   Check transmission fluid colour and smell — should be translucent red, not dark brown or burnt smelling.

3. 3

   Verify last fluid service date and mileage.

4. 4

   If shudder persists after a fresh fluid flush with correct specification, torque converter replacement is required.

Parts involved: Torque converter.

$400 to $3,200 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “When was the automatic transmission fluid last changed and with what specification?”
• “Have you noticed any vibration or judder at steady highway cruise speeds?”
• “Has a transmission shudder been diagnosed or any transmission work performed?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.