What are the reasons for oil leakage in Volkswagen transmission filter?
2 Answers
The reasons for oil leakage in Volkswagen transmission filter are: Poor sealing: Poor sealing gaskets in various parts of the transmission, damaged oil seals, loose fastening bolts, cracked transmission housing, excessive gear oil, or blocked transmission vent hole. Excessive clearance: Worn oil seals or flanges, excessive axial clearance, loose bearing seats and bearings, and the processing quality of sealing surfaces not meeting product drawing requirements. Oil leakage at oil seal shaft neck: Aging and deformation of oil seals, fallen oil seal springs, or incorrect installation direction can cause oil seals to lose their sealing function. New oil seals should be replaced and installed correctly with the spring side facing the oil. If the shaft neck is worn or dented, causing looseness with the oil seal and resulting in oil leakage, the shaft neck should be replaced.
As someone who has been working with Volkswagen vehicles for years, I've seen transmission filter oil leaks quite often. The most common cause is a deformed oil pan. Although aluminum alloy parts look sturdy, scraping the undercarriage or over-tightening the bolts can make it 'wrinkle,' resulting in an uneven sealing surface. The second most common issue is improper filter installation—like forcing a new filter in without completely removing the old gasket or applying sealant haphazardly, like squeezing toothpaste, and then tightening the bolts unevenly. I've seen cases where the transmission started leaking after just 200 kilometers post-filter replacement, and upon inspection, it turned out the rubber ring on the OEM filter was misaligned. For older cars, it's also important to watch out for fatigue and aging of metal gaskets, just like how rubber bands lose elasticity over time. Initially, the leak might just be a stain, but if ignored, it can progress to dripping oil and eventually saturate the entire transmission housing.
