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Discussion Starter · #1 ·
Hello, about two months ago I bought my first ///M car and second BMW and E39. I have been lurking on this board way before I got my M5 just to learn about them.

But now I have two problems, an annoying whine and squeaky brakes.

The whine: It is audible at anything above about 30mph with no throttle load (I have a muffler delete so the exhaust drowns it out), and becomes much louder at 45+mph. It is a "wooo" sound when off the throttle and a continuous "whoop" sound when on the throttle. Both sound almost like loud tire noise but a bit more high pitched. The noise seems to permeate through the transmission/driveshaft tunnel and I have had passengers say they can hear it more when sitting in the rear. Whether the clutch is in or out has no effect either. I also just replaced the transmission fluid with Redline and the differential fluid with Redline 75W-140 about 500 miles ago (the car has 101,400 miles on it by the way). From what I have read it could be the center support bearing or the differential, maybe even transmission bearings, but I would like the have more specific opinions based off my description because the noise doesn't match up with the ticking and metal-on-metal sounds people have described the CSB as, and the diff only whining with throttle application. And I would hate the spend my time and money replacing something that isn't the problem.

The brakes: my front brakes squeak at low speeds, and screech horribly loud when I am turning with a bit of brake pressure. I haven't found much or potential solutions on this: add anti-squeal compound and bed the brakes, both of which I have done to no avail. The pads are pretty new and the rotors are in good condition. Unfortunately I don't know enough about brakes to have any idea what to do next.

Any help on these issues will be greatly appreciated as they are driving me crazy. :crying:
 

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I'm in the same boat

That's funny. I just bought my first M and second bmw about 3 months ago and have exactly same your issues plus some more little things here and there. I took it to the dealer for inspection and found nothing. I changed transmission mounts and fluid. Changed rear end bushing and fluid and still the same. Break pads looks new and good rotors and make exact noise like yours specially after driving hard when I pull in to my driveway slowly and slightly braking it will squeak. I guess all these little things is normal for an old high performance car. As for brakes I guess rebuilding calibers and flushing system will fix all noises. Good luck
 

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What kind of brake pads are you both using? Squealing brakes shouldn't necessarily be a problem other than annoying.
 

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Subscribed.

I recently purchased my car with 103k and have the same noise from what sounds like the differential. Mine is only apparent at 43+ mph. I've also changed the diff fluid to no avail. I can clearly hear mine over the dinan exhaust. Noise mostly goes away when I take my foot off the gas.
 

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Discussion Starter · #6 ·
sikesrr: I honestly don't know the brand of brake pad that's on the car right now, I didn't check when I took the off last. And its not just annoying, it is so loud it gives me a headache.

68FB: Sorry, I'm not very good with descriptions. I'll try to post some sound clips soon, although because of the nature of the sound, I'm not sure how audible it would be.
 

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From my experience, stock pads do not squeal, they're just dusty, track pads screech like a MOFO when cold but stops on a dime. You win some you lose some.
 

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Would anti squeal compound on the brake pistons / pad ears help the squeal?

I'm about to try that as I've got some squeal too (not sure if it's from front or rear). I've got Stoptech 4 pistons up front, and the pins rattle like crazy over bumps so I'm going to try to bend them a bit to keep some tension on them.

Drivetrain noise, I agree a sound clip would be good, but I know how subtle some of these noises can be to try to capture... Good luck with it - and Merry Christmas! (I've just snuck onto the board on Christmas morning while no one's looking!).
 

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I have the same constant high pitched whine. Either the Center Bearing or the in the rear CV/Differential.

What differential oil are you running? My 540i has 175K miles and I've not had the same whine (older driveshaft, older differential)...

I'd put in Redline 75-90 but now am thinking of swapping in the 75-140 (both for LS applications).
 

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Discussion Starter · #10 ·
bimmerule: They might be track pads. When I get them really hot they stop squeaking, and they bring the beast to a standstill like it's nothing.

M5 Sydney: The backs of the pads are absolutely coated in anti-squeal compound. And merry Christmas to you as well.

ME_264: I put Redline 75W-140 in the diff that I bought from Turner Motorsports.
 

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Get her upto about 50 mph and shift her into neutral.......while coasting slightly weave back and forth in a single lane when you do this and try to hear where the noise is.

I had a wheel bearing that made some noise and I was able to determine it was a right rear.

I have a right front that needs looking at now.

Both are on my 540.

As far as brakes go they prob are some hard azz pads. Re-bed them by doing 5 or 6 60mph to 10mph brake applications(do not come to a complete stop).

In the M5 I used Redline 75W-140 in the diff and Redline MTF in the tranny.

Best of luck!

Be safe!

:M5launch:
 
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bimmerule: They might be track pads. When I get them really hot they stop squeaking, and they bring the beast to a standstill like it's nothing.
I think you found the answer to your first squeal. If bedding doesn't work, try swapping the pads out, which I suspect you will have to do anyway.
 

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Not trying to hijack the thread...just help. Maybe if your whine sounds like mine, we can both get help.

I took a video and was able to pick up the sound. I have the accelerator pressed constantly in the first part of the video and so the whine is constant. In the second half I modulate the gas on and off and you can hear the noise do the same.

I recently changed my diff fluid to Amsoil Severe Gear. No difference.

E39 M5 whine - YouTube
 

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Not trying to hijack the thread...just help. Maybe if your whine sounds like mine, we can both get help.

I took a video and was able to pick up the sound. I have the accelerator pressed constantly in the first part of the video and so the whine is constant. In the second half I modulate the gas on and off and you can hear the noise do the same.

I recently changed my diff fluid to Amsoil Severe Gear. No difference.

E39 M5 whine - YouTube
Now that's an annoying noise. Sounds like it's coming from the rear. It's unusually high pitched for diff noise in my experience, but the way it switches on and off as you load/unload the drive train means it's likely to be the diff gears. Has the diff been disturbed recently, pinion shaft seal for example?
 

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I went back and looked at the service records and the differential shaft seal front (connects to the drive shaft)(part #33121213949)<table border="0" cellpadding="0" cellspacing="0" height="2" width="136"><tbody><tr height="20"><td style="height:15.0pt;width:127pt" align="right" height="20" width="169">
</td></tr></tbody></table>was replaced right before I bought the vehicle.
 

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I went back and looked at the service records and the differential shaft seal front (connects to the drive shaft)(part #33121213949)<table border="0" cellpadding="0" cellspacing="0" height="2" width="136"><tbody><tr height="20"><td style="height:15.0pt;width:127pt" align="right" height="20" width="169">
</td></tr></tbody></table>was replaced right before I bought the vehicle.
That might be your problem. The large nut on the pinion shaft that preloads the supporting tapered roller bearings has to be removed to change that seal and if it is not reinstalled exactly back to the original location, the pinion shaft can move and change the contact area on the diff gear teeth, which causes noise. Member mattmor had the same problem recently.
 

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How would I go about getting it back to the original position if the person's mark who changed the seal, if there was one, is no longer there?
 

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How would I go about getting it back to the original position if the person's mark who changed the seal, if there was one, is no longer there?
A good question. If the noise is caused by the seal change, based on mattmor's experience, the best case scenario is the shaft and nut were well match-marked but the nut was screwed on one turn short. If that's the case, the pinion shaft will be loose enough in the brgs to move side to side. One more turn will correct it.

If the match marks are no longer visible, or it's not simply one turn short, that is more of a problem. There is a crush sleeve between the two pinion brgs that was compressed on initial diff assembly by tightening the shaft nut to the point it took a certain torque (a few in-lb) to turn the pinion shaft. The crush sleeve now allows the brg preload to be returned to that setting if the nut is removed. It acts like a strong spring and tightening the nut to it's original location compresses the spring to restore the correct preload.

The excellent article below explains how the preload can be restored to something like the correct value without having to remove and rebuild the diff. Driveline shops may be familiar with this technique.

Differential Pinion Pre-Load Adjustment.
 
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