RS3 Transfer Case Oil Leak Causing Gear Engagement Issues

Had the same symptoms on my S4 (2016) last winter. The oil leakage under the transfer case signaled worn seals, which allowed transfer fluid to escape and eventually led to gear wear. The repair involved a complete transfer case overhaul. Main issues found were: Damaged gear teeth from insufficient lubrication, Worn shaft bearings, Failed seals causing the oil leakage, Contaminated remaining transfer fluid This was a serious repair requiring specialized tools and expertise. The transfer case had to be removed completely. The mechanic replaced all worn gears, bearings, and seals. The work took 3 full days at the shop. Important: Continuing to drive with these symptoms risks catastrophic transfer case failure. The gear wear gets exponentially worse once oil levels drop below critical. Would strongly recommend getting it checked immediately before the transmission sustains permanent damage. The repair resolved all shifting issues and eliminated the oil leakage completely. Regular transfer fluid changes since then have kept everything running smoothly.

Thanks for sharing those details about the transfer case repair. The symptoms match exactly what I experienced with my 2019 RS3. My mechanic also found mechanical wear in several components due to low transfer fluid levels. The oil leakage started small but got worse quickly. How much did your repair end up costing? And has everything stayed smooth since the fix? Just wondering if any other issues popped up later, as I want to budget properly for potential future problems.

The total repair cost came to 330 Euro which covered fixing the defective gears in the transfer case. After getting it fixed by the mechanic, the transfer case oil wear issue was completely resolved and the transmission has been shifting perfectly for months now. The repair eliminated all oil leakage issues and restored smooth gear transitions. No additional problems have surfaced since the fix. Regular oil changes and monitoring fluid levels have kept the transfer case running optimally. To prevent future gear wear, the mechanic recommended checking transfer case oil levels every 15000km. This preventive approach helps catch potential leaks early before they can cause extensive damage to the gears and bearings. Given how the repair solved all symptoms, the cost was worthwhile to avoid more extensive transmission damage that could have resulted from continued oil leakage.

Thanks for the helpful advice. Finally got my RS3 fixed last week and wanted to share how it went. The mechanic confirmed the transfer case issues and found significant gear wear from the oil leakage. The repair took 4 days total and cost 2800 Euro, which included replacing several worn components and fixing the leaking seals. The grinding noise is completely gone now and gear shifts are butter smooth again. The mechanic showed me the old parts, the mechanical wear was pretty severe and would have definitely led to bigger problems if left unfixed. They also gave me a proper maintenance schedule to prevent future transfer fluid issues. Planning to stick to regular checks this time around to avoid another expensive repair. Lesson learned about not ignoring those early warning signs of gear trouble.