Differential Clink/Dink/Ping noise ?

[mrrm3]

I have an 2008 6 speed w/ 30k miles. It is out of warranty now.

In the past few months, I have noticed a new and annoying sound. When first starting to move forward in first gear (and sometimes when first moving in Reverse), I hear a metalic "clink," "dink" or "ping" (chose your description) coming from the rear end. Sounds like someone is making one distinct tap to the drive shaft w/ a ball pean hammer. (With the windows down in a parking struture, the noise is very noticeable.)

It only happens when loading the drive train. It may be the drive-shaft u-joint or the connection from the drive shaft to the differential. Possibly, it is the differential itself. (I sure hope not.)

I've done research on this forum. It is most definitely not rocks in the rotor shield. It is not a diff grinding noise when turning.

I changed the diff fluid and used the expensive stealer Castrol product w/ no results.

Thoughts or suggestions ?

Thank you in advance.

[Vic311]

99% of the time, fluid flush and change will cure this. Did you use the fluid with FM booster..this is key.

If that doesn't work, you could have something more serious going on

[Kasé Zomé]

I get that a lot after an aggressive drive, autox or track day. If you've driven aggressively lately and your MDM was working a good amount, you'll get this sound - esp. in reverse. A BMW Master Tech showed me just what to do and all you need to do is take a long screwdriver and push back the rear brake rotor covers. Easy fix.

[M3takesNYC]

Had it since day 1. totally normal. Some cars do it worse than others. The e46m3 did it also as it used the exact same differential. That is where the sound comes from

[leemik]

I had the same problem with my 09.. It started around 25k miles.. Never could figure out what the issue was. Though it was dct related.. It worried me because car was out of warranty. Dealership said it was normal noise..