After I had the oil changed on my two-year-old car, it became a bit noisy. I went to the dealer who told me that differential oil was drained and replaced with transmission fluid, which caused serious damage to the transmission. The shop claimed that only the oil was replaced. The dealer thinks that something has been done after the oil change because it is a couple of quarts over. I haven't messed with the car and I don't know what to do. Do you have any advice for this situation?
If you have a manual transmission this shouldn’t matter - both the transmission and rear differential take 75W-90 gear oil. If however, you have an automatic transmission, filling the front differential with CVT transmission fluid could be a real issue. I suggest you get a firsthand second opinion from a trained professional, such as one from YourMechanic. They can tell you for certain if the correct type of fluid is in your differential and properly service your differential fluid as necessary.
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