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Discussion Starter #1 (Edited)
I have 2001 with 35k miles –25k when I bought it.

The rear diff has recently been replaced – several members had posted a similar description of the fault and thus helped me conclude the fault.

Unfortunately I took the risk with a private purchase with no extended warranty. BMW are aware or fault with m5 diff and thus offered me an 80% Good will discount on the parts. It still left a hole in my pocket . But it cured the problem.

Now I have another whining noise – this is different to the dif, although similar in noise but more central to the car. Basically, it started after completing a track day event. The car excelled all physical senses and I really found a whole new personality to the M. However, I’m not sure if it was the road tyres that gave out after 5 laps or the rear antirole bracket – either way I went into a slide at about 100Mph. No damage other than ruined tyres, and a broken antirole bracket.

The whining noise doesn’t change with acceleration / deceleration, and seems to be coming from the front / central. Its very prominent and very noticeable in 3<SUP>rd</SUP> and 5<SUP>th</SUP>.gears. Its faint, but it’s a noise you know is there, and previously wasn’t. It’s most prominent around town, as I tend to be in 3<SUP>rd</SUP> and 5<SUP>th</SUP> gear quite a lot. It starts at about 1.2krpm .

I took the BMW mechanic out to listen to it, and he felt it was within tolerance limits, but couldn’t conclude what it was. He didn’t think it was dif. I agree with this.



He also said he could hear the clutch release bearing on the odd occasion – what does this sound like?


Any suggestions/advise welcomed. I would be really upset about a gearbox problem with this kind of mileage. I don’t abuse the car, and previous owner didn’t look like an abuser.


Eitherway It needs sorting as I hate driving it like it is.
 

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First of all, I´m glad you didn´t get hurrt when you spun.

The rear anti-roll-bar brackets are known weak points on the E39 M5s. Those need frequent inspection for cracks, or replacement with reinforced ones.

So, is it correct that the noise in question:

1. changes pitch with roadspeed
2. does not change pitch with load
3. does not change intensity with load
4. is strongest when in 3rd and 5th gears
5. is not audible below 1200 RPM

Please report how the noise changes when you:

6. drive in 3rd gear at the RPM where the noise is strongest and then declutch and let the car coast down

7. stand still and very slowly rev the engine

8. drive at different temperatures

Questinos:

9. at what RPM is the noise strongest in 3rd gear?

10. at what RPM is the noise strongest in 5th gear?

David
 

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Discussion Starter #3 (Edited)
DavidS said:
First of all, I´m glad you didn´t get hurrt when you spun.

The rear anti-roll-bar brackets are known weak points on the E39 M5s. Those need frequent inspection for cracks, or replacement with reinforced ones.

So, is it correct that the noise in question:

1. changes pitch with roadspeed
2. does not change pitch with load
3. does not change intensity with load
4. is strongest when in 3rd and 5th gears
5. is not audible below 1200 RPM

Please report how the noise changes when you:

6. drive in 3rd gear at the RPM where the noise is strongest and then declutch and let the car coast down

7. stand still and very slowly rev the engine

8. drive at different temperatures

Questinos:

9. at what RPM is the noise strongest in 3rd gear?

10. at what RPM is the noise strongest in 5th gear?

David
Yep - read lots of posts about the rear antirole brackets - Have ordered the reinforced brackets from beast power.
<O:p</O:p

RE the gearbox noise:<O:p</O:p

1. changes pitch with roadspeed - <O:p</O:p

very slightly, it gets harder to hear as the road speed increases, road noise drowns it out, but you can still hear it in the background<O:p</O:p

2. does not change pitch with load -<O:p</O:p

The pitch doesn't really change with load<O:p</O:p

3. does not change intensity with load - yes it seams to get louder when under load, but only in 3rd and 5th. I've noticed it again but much louder when piling on the load in 5th when accelerating hard from 4krpm onwards (warp Speed Mr Scotty) - however I was playing with a 911 C4
<O:p</O:p
4. is strongest when in 3rd and 5th gears - <O:p</O:p

most noticeable in 3rd and 5th gears. At the same rev ranges in 6th, 4th I struggle to here it. Yet when I swap to 3rd or 5th its instantly noticeable.<O:p</O:p

5. is not audible below 1200 RPM.<O:p</O:p

Its present at about 1Krpm when accelerating normally in 3rd / 5th. 4th or 6th I can't really hear it.<O:p</O:p

6. drive in 3rd gear at the RPM where the noise is strongest and then declutch and let the car coast down<O:p</O:p

Yes it does seem to go off when the clutch is depressed. However, <O:p</O:p

it also seems quite delayed - eg pressing the clutch didn't seem to instantly make it go away - more when the revs drop below 1200 Krpm <O:p</O:p

If I move from 3rd to neutral and release the clutch it goes off, If I rev the engine in neutral whilst coasting - nothing, as soon as put in 3rd or 5th its back again. <O:p</O:p

7. stand still and very slowly rev the engine <O:p</O:p

nothing<O:p</O:p

8. drive at different temperatures<O:p</O:p

I tend to notice it more when the car is warm, its possibly louder, when warm than cold.<O:p</O:p

9. at what RPM is the noise strongest in 3rd gear?<O:p</O:p

from 1Krpm to 2Krpm<O:p</O:p

<O:p</O:p
10. at what RPM is the noise strongest in 5th gear?<O:p</O:p

from 1Krpm to 2Krpm<O:p</O:p

I would also say that the whine is present from 2Krpm onwards - its just not as noticeable due to tyre noise / engine noise. However, you can still hear it. The noise itself is more of a harmonious whine.<O:p</O:p

Thanks for the assistance and any feedback<O:p</O:p

<O:p</O:p
 

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This is quite a puzzle...

Your answers so far have ruled out most of the explainations I can think of.

Am I interpreting you correctly regarding question 1: There is some change in pitch with roadspeed, but not nearly as much as would correspond to the change of roadspeed. ?

Two more questions, please:

11. If you drive in 5th gear above 2k RPM, and then take your foot completely off the accelerator pedal but leave the clutch engaged, how does the sound change as the car slows down through the revs?

12. If you drive at 2k RPM in 5th gear, how does the pitch of the sound compare to the pitch of the sound when driving at 2k RPM in 3rd gear?

David
 

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BTW, have you checked the oil level in the gearbox?

Remove the filler cap, and stick a finger into the gearbox. You should be able to feel the gearbox fluid. The closer this level is to the lower side of the filler cap hole, the better.

If there is not enough gearbox fluid, top it up until it overflows.'

David
 

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I'm sure you already realize this, but:

1) Whining that only occurs in certain gear(s) is usually coming from the gearbox, unless it's some odd situation that involves only first or 6th gear. In your case, the gearbox is the likely source. That said, I would first ensure the external shift linkage & shifter assy is not at fault...or vibration from misaligned hardware on the undercarriage, somehow causing the noise.

2) The Getrag gearbox is "not repairable" because parts are not sold to anyone. If you hold onto it for a decade or so, history suggests they may release parts for rebuild. Time will tell. Today, a bad box is only useful for sentimental value, collectability or core exchange when you buy a reman box thru BMW or authorized Getrag retailer (if any exist). Finding root cause is fruitless, since it can not be repaired.

3) I would live the whine, unless you can get a BMW dealer to replace it at reduced cost.

4) Perhaps your hearing sensitivity has improved?
 

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If the gear box is bad as Lscman suggests, one of our board members has gearbox for sale! These don't show up often, so you may want to check the For Sale section about the E39 M5 drivetrain for sale!!
Regards,
Jerry
 

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Discussion Starter #8
DavidS said:
This is quite a puzzle...

Your answers so far have ruled out most of the explainations I can think of.

Am I interpreting you correctly regarding question 1: There is some change in pitch with roadspeed, but not nearly as much as would correspond to the change of roadspeed. ?

Two more questions, please:

11. If you drive in 5th gear above 2k RPM, and then take your foot completely off the accelerator pedal but leave the clutch engaged, how does the sound change as the car slows down through the revs?

12. If you drive at 2k RPM in 5th gear, how does the pitch of the sound compare to the pitch of the sound when driving at 2k RPM in 3rd gear?

David
thanks for all the suggestions - I found something new with it today...
driven 300 miles in it today, and had lots of time to try different tests and finally worked out the way to hear it and create it.

The situation is as follows.

In 3rd / 5th, at anything from 1krpm to 2krpm - I hear the noise - perhaps not a whine , perhaps resonance (hard to describe). When I press the clutch in, whilst in 3rd/5th, and vary the revs between 1-2krpm - the noise doesn't go off as originally thought. My previous answer in reply to your post was based on letting the revs drop whilst pressing in the clutch.

When in 3rd/ 5th, with the clutch in, and holding the revs at 1.5krpm, and then slide into 4th/6th it goes off...instantly...put it back in 3rd/5th the noise is back. When releasing the clutch, 3rd/5th, the noise is possible louder - but only marginally.

I also repeated this test whilst the car was stationary...In neutral, clutch out, no noise, clutch in, sliding between 3rd and 4th...equates to noise ON...noise OFF. Same thing in 5th and 6th. However, 1st and 2nd doesn't seem to have the problem.

Any thoughts??? could it be Rogue SSK??? or could it still be the gearbox.

Like I said did 300 miles today, and didn't notice anything in 6th, but dropping to 5th it was back. I think I was more conscious of it before as I was driving a lot in 5th due to slow traffic on the motorway.

Anyway - thanks for input so far - don't think I can stomach replacing the gearbox":sad2:
 

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granville-fall said:
I also repeated this test whilst the car was stationary...In neutral, clutch out, no noise, clutch in, sliding between 3rd and 4th...equates to noise ON...noise OFF. Same thing in 5th and 6th. However, 1st and 2nd doesn't seem to have the problem.
One follow up question. when stationary and in neutral with the clutch out, the transmission input shaft is spinning. With the clutch in, and you go into 3 or 5, does the noise start and remain constant or does it die off since the input shaft would quickly spin down? I would think if you still get a noise when stationary and clutch in, the transmission internals aren't spinning and can't be the noise. I would now suspect a vibration between the shift mechanism and something but how and what?

LSCMAN, can the shift rails on the transmission (I think that's their name) be adjusted or repaired on the Getrag?
 

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granville-fall said:
thanks for all the suggestions - Any thoughts??? could it be Rogue SSK??? or could it still be the gearbox.

I got a buzzing in third w/ my Rogue SSK/DSR. Also had problems w/ the 3-2 downshift getting extemely notchy/hard to hit the gate. The former went away and the latter improved greatly after pulling it out. You could mildly feel the vibration in third thru the shifter when the 'buzz" was there.

Paul
 

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Very interesting observations. I think it is pretty much safe to rule out the gearbox internals.

I know some SSKs are extremely sensitive to the slightest misalignment in the gearbox and engine mounts. You may need aftermarket gearbox mounts.

There is a certan sequence in which those mounting bolts must be torqued in order to get as little vibrations as possible.

I would suggest to talk with the SSK manufacturer. They have perhaps encountered this phenomenon before.

Unless they have a better suggestion, I´d say: loosen all engine and gearbox mounting bolts, check all SSK linkage for correct fit and then retorque the mounting bolts in correct sequence.

David
 
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