Tried to get my Diff Fluid changed to fix the noise... BMW said No.

[calintexas]

Originally Posted by darkmercury

Good Point.
Ok... I'll think keeping the noisy diff is ok after reading a few posts regarding loss of performance.

I agree with not changing to the modified fluid after what has been said. The figure 8 procedure was recommended for the E46 M3's that had the noise.

[King Tut]

Originally Posted by darkmercury

It sounds like the tires are rubbing when only making slow tight turns... like in a parking deck. Comes from the rear of the car and you can even feel a slight vibration from it.
The faster I take the turns, the less it makes the noise. hahaha
Waited until the deck was near empty after working late, and tried it with a little speed.

I would say the time you would be most likely to hear it is when going to the gas station to fill up and you have to make tight turns to get your car around other cars and to the pump.

[markjord]

Dealer changed my diff oil. We argued about payment but eventually I won. The groaning noise from the diff on tight right turns (which was quite loud) has now gone. Difficult to detect any down side to this procedure so I'd recommend it.

[Gladius]

Originally Posted by SenorFunkyPants

Unless the diff noise is excessive you would be well advised to NOT change the diff for the one with extra slip agent. BMW provided the extra slip oil to pacify owners who complained about the diff noise thinking it meant the unit was malfunctioning and could not be convinced that the noise is perfectly normal. If the extra slip diff oil was a simple no downside benefit the oil would be used as a factory fill for the diff on manufacture, the simple fact that BMW doesn't do that is because they know it will degrade the performance of the diff.

Unless you have some proof of this it sounds like pure internet speculation.

[King Tut]

The fact is that more slip agent will reduce the locking of your LSD. It would be interesting to have someone who is complaining of the noise test the breakaway torque of their differential and then go get the new fluid installed and run the test again.

[darkmercury]

Originally Posted by King Tut

The fact is that more slip agent will reduce the locking of your LSD. It would be interesting to have someone who is complaining of the noise test the breakaway torque of their differential and then go get the new fluid installed and run the test again.

Good Point... We paid for performance and if the rear end makes noise and performs like it should, then keep on making that noise. If it really was destroying the Diff., then BMW would have to make the fluid change mandatory because broken rear end swaps would be expensive service work.

[///M Rakete]

Originally Posted by darkmercury

Good Point... We paid for performance and if the rear end makes noise and performs like it should, then keep on making that noise. If it really was destroying the Diff., then BMW would have to make the fluid change mandatory because broken rear end swaps would be expensive service work.

+1 Exactly. Now, it could be possible to have a differential that is borderline or slightly out of spec. I imagine it would sound really bad. In this case the oil with the friction modifier might be worthwhile from a longevity perspective.

We in the US, and maybe others elsewhere, tend to be finicky when it comes to sounds, etc. I'm not saying there isn't in some cases a real legitimate need or use for the friction modifier but if it didn't come that way and there is no SIB that says it doesn't come that way in order to promote break-in, well then there's the answer. In fact the SIB states "if a customer complaint is verified", not if the tech happens to notice. BMW undertook an engine software modification on the 335i as I recall because of wastegate noise. The result was the introduction of lag and then complaints about that.

[gthirtyfizle]

I went in for service last week and decided to let them know about the diff noise. I also let them know that I knew what it was and if they could change the fluid. To make a long story short they said no, and that i would have to have a tech test drive the car so they can replicate the sound. I was like fack that, Im out. lol.

[SenorFunkyPants]

The fact that BMW are now reluctant to make what is after all, a very fast and cheap diff oil change ought to at least suggest that its not the win-win fix it was once considered to be.

[BobsM3Coupe]

Anyone know what size allen (hex) is needed to R&R the fill and drain plugs on the M3?

I also called a few local dealers and the 2583 (SAF-XJ + FM Booster) differential fluid lists at $62.31 a liter, compared to $21.00 a liter for the regular 0080L SAF-XJ fluid. Like I stated earlier, BMW is saving a bundle by using the cheap stuff.

Of course, you can find the good stuff lower ($39.00) online.

[///M Rakete]

Originally Posted by BobsM3Coupe

Anyone know what size allen (hex) is needed to R&R the fill and drain plugs on the M3?

I also called a few local dealers and the 2583 (SAF-XJ + FM Booster) differential fluid lists at $62.31 a liter, compared to $21.00 a liter for the regular 0080L SAF-XJ fluid. Like I stated earlier, BMW is saving a bundle by using the cheap stuff.

Of course, you can find the good stuff lower ($39.00) online.

That's got to be a rip off of some sort due to sourcing or availability only from Germany. There's no way the friction modifier justifies such a price difference.

[Kenyon]

When you do the 1200 mile oil service the dealer uses Castrol SAF-XJ for the diff. The only time they'll use the BMW special diff fluid is when there's a complaint for the grinding noise which there is a bulliten for.

[Kenyon]

You need a 14 Hex for the plug

[BobsM3Coupe]

Originally Posted by Kenyon

When you do the 1200 mile oil service the dealer uses Castrol SAF-XJ for the diff. The only time they'll use the BMW special diff fluid is when there's a complaint for the grinding noise which there is a bulliten for.

The service tech is also supposed to road test and verify that the vehicle does indeed have the noise problem before they will put the expensive lube
($40.00 a liter compared to the SAF-XJ $12.00 a liter) in the differential.

[SenorFunkyPants]

Originally Posted by BobsM3Coupe

The service tech is also supposed to road test and verify that the vehicle does indeed have the noise problem before they will put the expensive lube
($40.00 a liter compared to the SAF-XJ $12.00 a liter) in the differential.

The cost to BMW of the SAF-XJ oil modified by themselves with some aftermarket slip additive is likely to be only a few dollars more than the standard SAJ-XJ..far more costly is tech time wasted test driving the car...how much is that in the USA...$200 an hour?? Cheapest option would be to just swop the oil whenever asked, the fact that BMW will no longer do so is telling not of cost but concern for the outcome.

[JCtx]

Originally Posted by Kenyon

The only time they'll use the BMW special diff fluid is when there's a complaint for the grinding noise which there is a bulliten for.

Originally Posted by BobsM3Coupe

The service tech is also supposed to road test and verify that the vehicle does indeed have the noise problem before they will put the expensive lube ($40.00 a liter compared to the SAF-XJ $12.00 a liter) in the differential.

That sounds like crap to me. Same part needing 2 different oils? That tells me one of two things: tolerances/quality are so crappy that some diffs have chatter while others not (with cheap fluid), and/or they don't care if your LSD craps out after warranty. Chatter is not good, no matter what BMW says. Cheap bastards. I guess we all need to complain. My car also got the cheap stuff (before I was aware of this 'new' fluid).

How about using Redline (or some other such oil) in there? It's going to be a lot cheaper than $40 .

[SenorFunkyPants]

But its not gear chatter or lash, its simply the clutch pack metal disks rubbing against each other as they unlock....of course you could always put in yourself some after-market slip additives, they are available over the counter in very small bottles for a few dollars, that way the clutch packs will be nice and quiet as they unlock with far less load....which I suppose I should point out is not a good thing!!

[Kyoshi71]

Back in the day, I built several rear differentials. It was always commonplace to put a diff additive in addition to 90w gear oil otherwise slow turning was unbearable. Even if you used synthetic gear oil. The additive never had any adverse effects on wear or traction ever.
What would be the harm in using an additive on the M (unless of course there was a warranty issue)

[B.Hallowell]

I had the diff noise and got the fluid replaced. They said it would take about 600 miles for it to settle in, which I called BS on because I figure it'd be almost immediate. Needless to say I did about 800 miles, still there. I brought it back in and they replicated it again. They kept my car for like 2 days and changed a bushing on the top of the diff... It worked. So in my case I had diff noise, new oil didn't work and they changed out a bushing and did some kind of witchcraft and it's much better. I really only still get it when it's cold and a very slow tight turn. Oh and I asked them to change it back to the original fluid after we found the bushing was the issue.

[KANdaddy]

OP...that sucks. i just had my diff oil changed for free at 29K miles. I didn't even go in for that as I've had no issues with it at all ......they just told me "oh yea...ur diff oil needs to be changed so we'll do that too."

[SenorFunkyPants]

Originally Posted by Kyoshi71

What would be the harm in using an additive on the M

The Diff relies on the friction between the metal disks in the clutch packs to work as designed...if you add additional slip additives you are enabling the disks to slip against each other far easier and thus quieter (its the clutch disks in these packs being forced to slip against each other under very high loads to allow the wheels to turn at different speeds when you make a turn which causes the rubbing groaning noise) but now obviously they will resist far less load before slipping which is not a desired outcome.
A bit like putting a bit of oil on the brake disks to reduce brake noise under heavy braking...yes it will make them quieter but at a cost in efficiency

[darkmercury]

I wonder if the 2010 and 2011 M3's will make the same noise? Time will tell...
If not, then maybe they are using the newer fluid from the factory.