[mimsterzx7r]

Wow I had no idea that the Dinan diff has had issues like this. I was really looking into doing this mod but held off because of the eternal 3.91 vs 4.1 debate. Would polished gears make a difference for this problem.

So what do you guys think? Which way would you go at this point Dinan, Diffsonline, Turnermotorsport? Core exchange vs ring and pinion gear set?

I was researching on the M3 forums and some of the more popular opinons were
1. There is a bit of whine normally from even the stock diff, some diffs more than others
2. Greater whine from improper breakin
3. Greater whine from improper diff fluid
4. Whine is reduced from using polished gears.
5. Of course improper installation.