Hyundai Santa Fe: A6MF2 Torque Converter Shudder at 80-100 km/h

The DM Santa Fe's 6-speed A6MF2 automatic transmission is documented to develop torque converter clutch (TCC) shudder at steady highway cruise speeds between 80 and 100 km/h. The shudder manifests as a vibration through the floor and seat that mimics a misfire or rough road surface, occurring as the TCC lockup clutch slips under light throttle load. Root causes are degraded ATF losing friction-modifier properties and worn TCC clutch material. Hyundai issued updated ATF specifications and flush procedures as first-line remediation; however worn clutch packs require torque converter replacement. Affects both the diesel and petrol variants fitted with this gearbox.

• Vibration or shudder felt through the floor and seat at 80-100 km/h cruise on light throttle
• Shudder disappears when throttle is increased or lifted off sharply
• Feels similar to driving over a rumble strip at sustained highway speed
• Symptom is intermittent at first and worsens as transmission temperature rises

1. 1

   Test drive at a sustained 80-100 km/h on a smooth flat road under light throttle load and hold speed for at least 60 seconds.

2. 2

   If shudder is present note whether it clears immediately when accelerating harder.

3. 3

   Check ATF colour and condition via the dipstick or drain plug — dark brown or burnt-smelling fluid indicates overdue service.

4. 4

   Request the automatic transmission fluid service history.

Parts involved: Torque converter.

$200 to $5,000 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.

• “Has the automatic transmission fluid ever been changed, and if so when and with what specification?”
• “Has any shudder or vibration been noticed at highway cruise speeds?”
• “Has the transmission been inspected or serviced at a Hyundai dealer?”
• “Are there any transmission warning lights or fault codes in the service history?”

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.