Thank you all for the replies and advice! I figured it would be best to try and replace the gear and replace the oil! I will pick up the car and take it home tomorrow. Any recommendations on which brand gear to buy?
I saw this one from Amazon:
https://www.amazon.com/MTC-122053-Tr...ustomerReviews
and I saw this whole rebuild kit from ECS Tuning:
https://www.ecstuning.com/b-genuine-...QaAhNnEALw_wcB
Should I go for the Genuine BMW part or go with the Amazon part hoping it'll last and has no manufacturing defects shown in the photos in the review section.