Are the fill and drain plugs still a 17mm internal allen head plugs on my 2002 330xi?
If my rear differential turns out to be bad, where would you suggest to get it rebuilt or a new one ordered?

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This post was auto-generated based upon a question asked on our tech article page here: Pelican Technical Article: BMW E30 3 Series Differential Oil Change

I'm not sure about the size - they have made so many changes over the years! :) Actually, just looked our photo on that plug, it does still look like a 17mm internal Allen head. Differentials typically don't wear out - I'm going to copy your question here to the forums so that we can get more information on what the problem is exactly.

- Wayne

What indication do you have that your diff may be bad?