Audi S5 Trans Issues: Rough Shifts Point to Oil Trouble

I had a similar issue with my 2019 Audi S4 last year. Having some experience with transmission problems, I recognized the symptoms you describe, especially the rough shifting and delayed gear engagement. The root cause in my case was mechanical wear in the transfer case gears. Initially, I thought it was just old transfer fluid, but the mechanic found more serious problems during inspection. The workshop confirmed the transfer case needed partial rebuilding due to worn components. The complete repair, including new transfer case oil and replacement of defective gears, cost me 330 Euro. The job took about 6 hours at the shop. Before you proceed with repairs, could you share: Current mileage on your S5? When was the last transfer case oil change? Do you hear any unusual noises during acceleration? Does the problem get worse after the car warms up? This information would help determine if your issue matches what I experienced. These symptoms can sometimes indicate different problems in the transfer case or transmission system, so getting an accurate diagnosis is important. The workshop should definitely check the transfer fluid level and condition first, then perform a thorough diagnostic of the transfer case operation. Regular transfer case oil changes can prevent similar issues in the future.

I can confirm my current mileage is 158040 KM and my last service was done just 2 months ago. During acceleration, I notice a distinct grinding noise, especially between second and third gear. The problem does worsen after about 15 minutes of driving when the car is fully warm. The symptoms appear to match your experience with transfer case issues. My main concern is the oil leakage I recently noticed on my garage floor, which could explain the rough shifting you mentioned. The transfer case oil might be critically low, contributing to increased gear wear. Based on the repair cost you shared at 330 Euro, this seems like a reasonable fix if the diagnosis confirms similar problems. The 6-hour repair timeframe helps me plan accordingly.

Thanks for sharing those details. The grinding noise between gears combined with the oil leak raises some red flags that sound very familiar based on my S4 experience. The symptoms you describe, especially the gear grinding getting worse when warm, strongly suggest this is beyond just low transfer fluid. When I had my transfer case rebuilt, the mechanic showed me how the gear wear had created metal particles that were circulating in the system. Since youre seeing active leakage, the immediate priority should be preventing further gear wear from low fluid levels. My repair actually ended up being relatively straightforward because we caught it before the wear became catastrophic. A few things to watch for in your case: Check if the grinding sound changes intensity during turns, Note if the transfer fluid on your garage floor has a metallic shimmer, Monitor if the gear engagement delay is consistent or unusual The 158040 KM reading is quite close to where my issues started developing. While the recent service is good, transfer case oil checks arent always included in standard maintenance. Given the similarity to my case, I recommend getting it checked soon, as running low on transfer fluid will accelerate gear wear significantly. The 330 Euro repair cost could increase if additional gear damage occurs.

Thank you for detailing your observations. Given the grinding noise and oil leakage appearing after recent service, getting this checked quickly makes sense to prevent further damage. My situation seems quite similar to yours, especially the gear grinding noise increasing with engine temperature. The oil leakage on my garage floor definitely explains the rough shifting and delayed gear changes. Your experience with metal particles in the transfer fluid makes me nervous about potential internal damage. I checked again after reading your reply and noticed the transfer fluid leak does have a slight metallic sheen. The grinding is definitely more noticeable during left turns. As for the gear engagement delay, it happens most consistently when shifting from second to third gear. Given my 158040 KM mileage and these symptoms, I will schedule a transfer case inspection immediately. The 330 Euro repair cost seems reasonable compared to risking more extensive mechanical wear. I appreciate you mentioning the 6-hour repair time, helps me arrange transportation. Will make sure they thoroughly check both the transfer case oil level and condition. Thanks for helping confirm my suspicions about these transmission problems. Better to address it now before the gear wear becomes more severe.