[bigshooter]

I'm posting about this again after attempting multiple repairs, all without success. I am beyond frustrated.

2014 328d w/ Kerma Stage 2 engine and tranny tune. On Bilstein B14 coilovers, M3 replica 437Ms staggered

Immediately upon driving there is not really any noise. Once I get up to about 40 mph or after a minute or 2 of driving, the scraping noise starts. It sounds rotational, like something is not lubricated.

It does not change with the speed of the car. I can feel the vibration front under my feet.

Occasionally, after going around a slight corner or something like that, it will make a nasty grinding noise and then just go back to just the scraping noise.


After my last thread, Enabled suggested cupped tires. He was right, they were cupped, so I replaced them...

I now have:
- 4 brand spankin' new tires
- new center support bearing on driveshaft
- new rear diff guibo joint ( T case & front guibo replaced by dealer 20k miles ago under warranty)
- new front wheel bearings installed yesterday

I currently have my B14s as low as they can go on the front.
I have not had any axle issues. The boots look brand new, even at 130k miles.
There is no play in the wheel bearings
When doing figure 8's or going around a corner, the noise does not get better or worse either direction.

Two things I noticed:
1) The noise goes away upon acceleration when the front end lifts slightly. (Taking weight off the front end). When braking, it becomes slightly more pronounced.
2) The noise kind of goes away when I put on my stock 17s. When I put my 19" staggered wheels on, the noise comes back. Please note that I've been driving on these wheels AND the exact same tire brand & model for the past 5 years. It is not related to the wheels or tires.

Because of this, it makes me not think it's the rear wheel bearings. There is some scraping noise spinning them while in the air, but I attributed it to the brakes.

All I can think of is:
- rear wheel bearings resonating through chassis and making it sound like they are coming from the front
- front diff is shot
- front prop shaft
- broken axle support bracket/diff support bracket?

I've been chasing this noise for weeks. This is the closest video I can find to the noise. In his case it was a rear wheel bearing. My rear wheel bearings have never been changed. Fronts are brand new with < 10 miles on them. I don't think it's my rears because i can feel and hear it under my feet right where the diff is. I know bearing noise can play tricks on you though...

Can anyone help here?

[1QuikWS6]

Just throwin it out there - IDK if the 328 has the same issues with the parking brake cable mount breaking like the other models - typical on the others that there is a plastic dual bracket that is under the car in tunnel location right where you are hearing/feeling the noise vibration.

The bracket breaks & allows the parking brake cable to fall down and come in contact with the driveshaft which depending on acceleration & suspension positions would make an awful scraping/screeching noise intermittently

You will be able to see it clearly once under the car & look where the dual cables run along the top of the driveshaft.



There is an aftermarket bracket fix (AGA Tools Park Cable Clip Repair Kit) for this that replaces the plastic bracket with an aluminum version & does not require the BMW recommended replacement procedure of removing the driveshaft, dropping exhaust/heatshield, & lowering the gas tank & charging $700

Threads:

https://f30.bimmerpost.com/forums/sh...&highlight=aga

https://f30.bimmerpost.com/forums/sh...&highlight=aga


Bracket can be found here:

https://x-ph.com/aga-tools-park-cable-clip-repair-kit/

I replaced my bracket with the AGA version proactively b4 OEM failure

[bigshooter]

Yeah that's not gonna be it. I've seen that video before trying to track down a video of anyone having this issue. I'm starting to think it's a bearing inside the front diff. I saw some people have had some issues with cracking axle support brackets/cracked diff support brackets after hitting pot holes. Roads are horrible where I live. Would a damage bracket cause this noise?

I really don't want to do the rear wheel bearings this weekend and still have this noise. Because that would mean I probably need a front diff, and I would rather just spend the time figuring out how to get it out...

[bigshooter]

I cannot find a single post with anyone experiencing the same noise. A couple close but nothing exact. I can tteven find any posts about people having front diff issues. Today I stumbled across this article on diff repair. This is the rear diff but my noise sounds similar excluding the “blip” hrs doing to make it sing (if you read how he can manipulate the noise). I just have the scraping grinding noise. Seems like I might need a front diff.

http://fixyourdifferential.weebly.com/