Q7's Transmission Grinding: Torque Converter Lock-up Issue

Had similar symptoms with my A6 3.0T from 2013. The automatic gearbox showed identical behavior, rough shifting, grinding during gear changes, and warning lights. Initially thought it was a basic transmission repair, but diagnostic testing confirmed a lock-up clutch malfunction in the torque converter. The converter failure turned out to be more serious than expected. Required complete removal of the transmission to replace the torque converter assembly. The metal particles from the damaged clutch had contaminated the transmission fluid, which could have led to more extensive damage if left untreated. The repair involved: Removing transmission, Installing new torque converter, Replacing transmission fluid and filter, Flushing transmission lines, Programming the new converter This was a major repair job taking 4-5 days at the shop. The symptoms you describe match exactly what happened with my car. Would strongly suggest having this checked soon, as continuing to drive with a faulty converter can cause additional transmission damage. The repair resolved all issues completely, no more grinding, smooth shifting restored, warning lights cleared. Still running perfectly after 40000km.

Thanks for sharing your A6 experience, this really helps since I am dealing with similar engine surge and transmission problems in my Q7 right now. The symptoms match perfectly, especially the rough shifting and warning lights. I am worried about the torque converter replacement you mentioned since it sounds like an expensive fix. Could you share how much you paid for the complete automatic transmission repair? Also curious if you have had any other transmission issues pop up since the repair was done?

After getting the automatic transmission repair done at a specialized shop, the total came to 2120 Euro. The fix focused on the defective torque converter lock-up clutch, which was exactly what the diagnostic had indicated. The automatic gearbox has been working flawlessly since the repair, no more rough shifting, grinding noises, or warning lights. The transmission repair included a complete torque converter replacement along with new fluid and filter. They also performed a thorough system flush to remove any metal particles that could damage other components. Its been over 30000km since the fix, and the automatic transmission performs like new. No issues have occurred since then. The shifting is smooth, and there have been zero warning lights. While the cost was significant, addressing the problem early prevented more extensive transmission damage that could have been much more expensive. If your symptoms match what I experienced, getting it fixed sooner rather than later is crucial. A failing lock-up clutch can quickly lead to complete transmission failure if left unattended.

After getting multiple repair quotes, I finally took my Q7 to a transmission specialist recommended by other owners online. The converter failure diagnosis was spot on, they found metal particles in the fluid from the damaged torque converter clutch. The repair took 5 days total. They had to remove the entire automatic transmission to replace the torque converter assembly. The final bill came to 2350 Euro including: New torque converter, Transmission fluid change, System flush, Filter replacement, Computer reprogramming It was expensive but worth it to fix it properly. The engine surge is completely gone now and the transmission shifts perfectly smooth again with no more grinding or warning lights. Really glad I caught the converter fault early before it caused more damage. Been driving it for about 3 months since the repair (around 5000km) with zero issues. The specialist did a much better job than my old mechanic would have. Sometimes paying more for the right expertise saves money in the long run.