Weird rubbing noise when turning, Rear Diff?

[E92Adan]

I think this has been addressed on here before. But when making turns, specifically lower speeds on a turn, there is a sort of groan/rubbing noise coming from the bottom of the car. I’ve heard that is usually the rear diff and the fluid just needs to be changed. I just got it changed recently and it is still making that noise. I think the weather being 40 degrees also affects it because it has gotten worse/louder now compared to the summer when it had just started. Any ideas on what I would need to do to get this fixed. I used the Redline diff oil. 59k miles on the car.
I will try to add some videos on here.

[spammysammich]

Either tire rub or LSD. Get used to it or put slip additive in your diff oil. Your first time with a car that has an LSD? They all bind to some extent. Especially if they have an aggressive lockup. If you do a flush and use regular diff oil that meets bmw spec but doesn’t have slip additive, this is par for the course.

[E92Adan]

Originally Posted by spammysammich

Either tire rub or LSD. Get used to it or put slip additive in your diff oil. Your first time with a car that has an LSD? They all bind to some extent. Especially if they have an aggressive lockup. If you do a flush and use regular diff oil that meets bmw spec but doesn’t have slip additive, this is par for the course.

This is the kit I used. Yes my first LSD car. So would I need to put on some slip additive? Not sure if this red line one includes any modifiers or anything. It’s just very annoying because i know feel like I have to take it easy every turn lol.

[E92Adan]

Originally Posted by spammysammich

Either tire rub or LSD. Get used to it or put slip additive in your diff oil. Your first time with a car that has an LSD? They all bind to some extent. Especially if they have an aggressive lockup. If you do a flush and use regular diff oil that meets bmw spec but doesn’t have slip additive, this is par for the course.

https://www.fcpeuro.com/products/bmw...SABEgL4uPD_BwE

[spammysammich]

I wouldn’t bother. That’s how I know it’s working. But if you really hate it figure out what slip additive bmw recommends. Regular redline doesn’t have any as I recall.

[E92Adan]

Originally Posted by spammysammich

I wouldn’t bother. That’s how I know it’s working. But if you really hate it figure out what slip additive bmw recommends. Regular redline doesn’t have any as I recall.

Awesome I’ll take a look, it just annoys me because then I feel like something is wrong 😂
Thanks for the help brother : )

[pirategenes]

That's the wrong gear oil. Either add friction modifier to it, or you could use this Red Line gear oil:
https://www.fcpeuro.com/products/5w1...-1-quart-57914

This is what I use and it works great on both street and track. Good luck

[E92Adan]

Originally Posted by pirategenes

That's the wrong gear oil. Either add friction modifier to it, or you could use this Red Line gear oil:
https://www.fcpeuro.com/products/5w1...-1-quart-57914

This is what I use and it works great on both street and track. Good luck

I sent the wrong link actually lol will find it in a sec

[Reddevils7]

Can you post a video of the noise?

[E92Adan]

Originally Posted by pirategenes

That's the wrong gear oil. Either add friction modifier to it, or you could use this Red Line gear oil:
https://www.fcpeuro.com/products/5w1...-1-quart-57914

This is what I use and it works great on both street and track. Good luck

Yup just confirmed, this is the one I bought. The link you sent is correct 👍
Still makes the noise though may need additive.

[BP709]

Originally Posted by E92Adan

I think this has been addressed on here before. But when making turns, specifically lower speeds on a turn, there is a sort of groan/rubbing noise coming from the bottom of the car. I’ve heard that is usually the rear diff and the fluid just needs to be changed. I just got it changed recently and it is still making that noise. I think the weather being 40 degrees also affects it because it has gotten worse/louder now compared to the summer when it had just started. Any ideas on what I would need to do to get this fixed. I used the Redline diff oil. 59k miles on the car.
I will try to add some videos on here.

This is a well know issue with the differentials in e46 M3, e9x m3, e6x m5/m6, and e8x z4m. There is even a service bulletin about it. I only use the genuine BMW SAF XJ + FM booster Motorsport fluid and then follow the procedure in the bulletin to coat the clutches after the correct fluid is in the differential. Never had a issue with my m3 or countless customer cars. It’s expensive as you need 3 bottles but it works. Google BMW SIB 33 01 02

[djsilverjohnson]

I changed mine with a name brand labeled "for LSD differentials" but I still had to add a container of friction modifier to quiet it down.