Groaning from rear end

[HighSchoolDream]

At the beginning of my drive, from a complete stop is a left hand turn that I take at almost full steering lock. There has been a slight groan that has recently gotten worse. I have changed rear diff fluid with correct bmw oil from dealer. No change. I recently swapped my old style diff mounting bolts to the updated version and I’m not sure if that made issue worse or was just a coincidence. I’ve googled and read similar issues with worn spring pads but I think I’d hear it in other conditions if it was that. I also read that the lsd usually wears out at around 70k miles and I’m right about there. anyone experience this kinda sound before their lsd wore out? Other than going through and checking torque on all the bolts back there what else should I do? Trying to go through process of elimination from cheap and easy to hard and expensive. Going to start daily driving this car soon and want to get things sorted first. Please help

[FBloggs]

Does the car have poly bushings?

[Ramps]

I had the same issue and also swapped back to the OE fluid, it didn’t fix it right away but after a few thousand kms of spirited driving the noise seems to have disappeared. Maybe give it some more time?

[M3GA]

Try 8-10 hard figure 8's in an open parking lot (post-oil change)

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[BMWahba]

+1 on figure 8’s. From what I’ve heard and researched, our diffs are pretty stout, and shouldn’t fail that early.

[Estoril]

Which diff fluid are you using and how old is it?

[Apex_80]

I have found that nowadays the fluid dealers give is not correct as it doesn't have the FM that was originally spec'ed for our cars. Sounds exactly like the noise that my diff made when I purchased diff fluid from the dealer the first time, I searched out the correct fluid with the FM in it and within 100miles of driving the noise was gone.

[SteelGreyM]

Recheck the fluid level and do figuire 8’s lock to lock. Then recheck!

Also lsd isn’t gone after 70k...

[HighSchoolDream]

This is the fluid I’m running, not sure exactly when I changed it but less than 2yrs and barely any miles. I’ll do figure 8s again and double check the level.

as far as I kno I’m on all factory bushings so I don’t think I have any poly. I will finally get around to putting in new rtabs when I get the tool in maybe that will help.

I did resd that a cracked spring or worn spring seat could make A similar sound. Took a photo from a bad angle and spring didn’t look cracked, I’ll get a better look at in soon. Rubber spring seat looked bad though I’ll order new onEs, hopefully they’ll help with a little nvh if nothing else

[HighSchoolDream]

Recheck the fluid level and do figuire 8’s lock to lock. Then recheck!

Also lsd isn’t gone after 70k...

I had heard about the lsd on an E46 m3 YouTube channel. Guy is pretty legit so just took him at his word, I think I looked into it a bit but mostly only seen really old posts about guys getting then fixed under warranty. I can try to get the links together if anyone is interested