Toyota Prado: A750F Automatic Transmission Torque Converter Shudder

The A750F five-speed automatic transmission fitted behind the 1GR-FE V6 petrol develops a torque converter lock-up clutch shudder. The shudder occurs when the converter clutch applies in 4th or 5th gear at light throttle cruise speeds between 60–100 km/h. The friction material on the lock-up clutch glazes or wears, and the ATF breaks down, causing the clutch to chatter rather than engage smoothly. Many owners mistake this for an engine misfire. The condition is confirmed by the shudder disappearing when the accelerator is fully released or when the transmission is shifted to a lower gear. Toyota specified a drain-and-fill ATF change as the first corrective step, but in advanced cases the torque converter requires replacement.

• Rhythmic or pulsing vibration felt through the floor and seat at 60–100 km/h at light steady throttle, resembling an engine misfire
• Shudder disappears immediately when throttle is released or when the gear selector is dropped to 3rd or Sport mode
• Condition worsens progressively with mileage and is significantly worse when ATF is due for replacement
• Occasional hesitation or hunting between converter lockup and slip states at cruise speeds

1. 1

   Drive the vehicle at a steady 80 km/h on a flat road with light throttle.

2. 2

   A shudder felt through the floor, seat, and steering wheel in a regular oscillating pattern at this speed indicates torque converter lock-up clutch shudder.

3. 3

   Confirm the ATF is not burnt or dark — fresh ATF should be red and clear.

4. 4

   Check transmission service history for fluid change intervals.

Parts involved: Torque converter.

≈A$280 to ≈A$3,220 at independent workshop rates, shown as an approximate guide in Australian dollars. That is for this job on its own, not for the car.

An estimate, converted to Australian dollars, 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.

• “Do you feel any vibration or shudder through the car at around 80 km/h on light throttle?”
• “When was the transmission fluid last changed, and has it ever been changed?”
• “Has a transmission specialist ever diagnosed the vehicle for torque converter issues?”

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.