S4 Transfer Case Leak Causing Rough Transmission Shifts

Had similar symptoms with a 2007 Audi A4 2.0T. The transfer case issue started with minor gear oil spots, which quickly developed into a serious mechanical wear problem. The main symptoms matched yours, rough shifting, particularly between first and second gear, plus visible oil leakage underneath. Despite initial suggestions of normal wear, the transfer fluid loss was causing significant damage to the internal components. The repair required complete transfer case overhaul, including replacement of worn synchro rings and bearings. The gear grinding was caused by metal particles in the transfer case oil due to excessive wear on the gear teeth. This is not a normal wear situation, transfer case oil leaks often indicate internal damage that will worsen quickly. The slipping sensation typically means the gears are already experiencing substantial wear. Without proper repair, this can lead to complete transmission failure. Key warning signs to note: Oil spots under vehicle, Grinding noise during gear changes, Progressive worsening of shift quality, Slipping sensation during acceleration Recommend getting a second opinion from a transmission specialist. This repair cannot be postponed as continued driving risks more extensive damage to the transmission system.

Thanks for sharing your experience. Sorry you went through that gear grinding nightmare. My S4 had almost identical symptoms. Turned out the transfer fluid leak was causing severe gear wear, just like in your case. Got it fixed about 3 months ago. Really curious what the repair cost was in your case. Also wondering if youve had any other transmission issues pop up since the repair? My mechanic mentioned keeping an eye on the oil change intervals to prevent future problems.

Thank you for the follow up. The transfer case oil issue was completely resolved after the repair. The total cost came to 330 Euro for replacing the defective gears in the transfer case. This included new seals and fresh transfer fluid. Since fixing the gear wear problem, the transmission has been shifting smoothly with no additional issues for over two years now. Regular gear oil changes are crucial, I now check the transfer case oil levels every service interval to catch any potential leaks early. The repair shop found that excessive mechanical wear had damaged several gear teeth, which explained the grinding sensation. The new parts solved both the transfer fluid leak and the rough shifting completely. Your mechanic is absolutely right about maintenance intervals. Fresh transfer case oil helps prevent metal particles from accumulating and causing premature gear wear. Much cheaper to maintain properly than to fix another major failure.

After getting a second opinion, I found my mechanic was wrong about normal wear. The transfer case oil leak was causing serious damage, with metal shavings in the fluid from worn gear teeth. The grinding noise during shifts was a clear warning sign. Had it fixed last month, complete transfer case rebuild with new bearings and synchros. Cost me 2800 Euro total but the shop did excellent work. No more gear grinding or fluid leaks. Transmission now shifts perfectly smooth again. Learned my lesson about ignoring early warning signs. Going to stick to strict oil change intervals from now on. The mechanic showed me the worn parts, definitely not normal wear like originally claimed. Really glad I got that second opinion before the damage got worse. The whole experience reinforced how important regular maintenance is, especially checking transfer fluid levels. Much rather pay for preventive service than another major repair. At least the car is running great now.