LSD Break in procedure with picture!

[VanM3Lover]

Would you like to drive as described in the picture for 30 minutes?

My diff makes rubbing noise and chattering noise on very tight turns, maybe it's just not broken in.

[Gladius]

I don't know about this procedure, but what you are describing is a known issue. Take it to the dealer and ask them to look up the TSB on it. They will replace the diff fluid with a new fluid that will "fix" the issue. I had mine done last week.

[foosh]

For everyone who experiences this noise and has it quieted with a diff fluid additive, don't be surprised if the noise comes back. To some extent, it is the clutch packs in the LSD doing what they are designed to do. The noise is not indicative of any damage being done, and you can ignore it indefinitely.

Many will never hear it because they don't routinely make prolonged tight turns at low speeds (e.g. looping up or down in a multi-deck parking garage or as in the diagram above).

This noise is relatively common in all autos equipped with LSD and large tires. The LSD clutch packs are there to allow the inner tire to barely rotate, while the outer tire is rotating at a much greater relative rate. In tight turns at higher speeds, the relative difference in wheel rotation between inner and outer tires is minimal.

[MyKmYk]

Originally Posted by foosh

For everyone who experiences this noise and has it quieted with a diff fluid additive, don't be surprised if the noise comes back. To some extent, it is the clutch packs in the LSD doing what they are designed to do. The noise is not indicative of any damage being done, and you can ignore it indefinitely.

Many will never hear it because they don't routinely make prolonged tight turns at low speeds (e.g. looping up or down in a multi-deck parking garage or as in the diagram above).

This noise is relatively common in all autos equipped with LSD and large tires. The LSD clutch packs are there to allow the inner tire to barely rotate, while the outer tire is rotating at a much greater relative rate. In tight turns at higher speeds, the relative difference in wheel rotation between inner and outer tires is minimal.

Fantastic answer.

[GT3 Tim]

Originally Posted by MyKmYk

Fantastic answer.

Yep. Great answer.

If you want to hear LSD noise, jump in a 996 GT3! LOL. That phucker sounded like a Mr. Coffee machine on overdrive. LOL. perk perk perk...that's how I described it to a fellow owner....and it does sound like a coffee maker "perking", but x1,000. lol

LSD noise is what it is. They make noise. If yours doesn't, THAT is when I would be worried!

[Kobaiyashi]

Just to be clear, is this the click, click, click noise (like a stick rubbing across a bicycle wheel) that I hear when I am turning in the parking garage or on a onramp?

[GTM]

Originally Posted by VanM3Lover

Would you like to drive as described in the picture for 30 minutes?

My diff makes rubbing noise and chattering noise on very tight turns, maybe it's just not broken in.

That procedure is recommended by aftermarket clutch type LSD manufacturers.

[Dascamel]

30 minutes seems very excessive? Your LSD probably doesn't see that much wear from a few track days.

[erio]

Mine started making a rubbing type sound at about 3000 miles and only with slow sharp right turns. It does it very sporadically and really sounds like it's something coming from the front of the car. In fact, I had to take it to the service center 3 times because it was so inconsistant. It does seem to fade when the car is warmed up a bit. I took it to the head tech thinking it was the LSD and he said it doesn't sound like a differential and has no idea what it could be.....? Anyone think this could be the LSD and why only with right turns?

[foosh]

Originally Posted by erio

Mine started making a rubbing type sound at about 3000 miles and only with slow sharp right turns. It does it very sporadically and really sounds like it's something coming from the front of the car. In fact, I had to take it to the service center 3 times because it was so inconsistant. It does seem to fade when the car is warmed up a bit. I took it to the head tech thinking it was the LSD and he said it doesn't sound like a differential and has no idea what it could be.....? Anyone think this could be the LSD and why only with right turns?

There is a clutch pack for each half-shaft on each side of the diff. Slight differences in lubrication on one or the other clutch pack could cause one to make more noise than the other.

[LateBraking]

I saw the picture, read the title, too lazy to read through the rest.

This noise is normal in M cars, it's the clutch plates in the differential. The same noise comes out of my M3, and every other M3 really, if you try to listen for it.

If it really bothers you, then you can get an additive put inside your differential oil at the dealership. It will eliminate the noise by 2-3 days once added.

But really, it's not harmful to your differential, and it's all just a part of the M experience. If you wanted something without any quirks, you probably got the wrong car. M car's have a history of being quirky.

[FifthStreetz]

My car doeant have that noise? Should i be concerned? Lol seems like having that noise is a good thing?

[VanM3Lover]

Originally Posted by FifthStreetz

My car doeant have that noise? Should i be concerned? Lol seems like having that noise is a good thing?

What's your milage? I started hearing the noise 300 miles after the 1200 miles break in service.

[foosh]

Correct, you're likely to start hearing it after the LSD has gotten fully broken in. However, you may never hear it if you never do very tight, very slow and sharp turns.

[FifthStreetz]

Originally Posted by VanM3Lover

What's your milage? I started hearing the noise 300 miles after the 1200 miles break in service.

5000.

[LateBraking]

Like I said, if it's the cause of concern, sleepless nights, and countless nightmares, go ask for the additive to be put in. However, just keep in mind that whenever any oil services are done to your differential, you will have to ask for the additive every time.

Not like you change your diff oil every 1k mile or anything ridiculous, but still something to keep in mind.

Personally, I like the noise. Reminds me that the M is an M.

[consolidated]

Mine moaned like mad until I took it to the track, all gone except for the first tight turn on colder mornings.

[jbeene]

Originally Posted by foosh

For everyone who experiences this noise and has it quieted with a diff fluid additive, don't be surprised if the noise comes back. To some extent, it is the clutch packs in the LSD doing what they are designed to do. The noise is not indicative of any damage being done, and you can ignore it indefinitely.

Many will never hear it because they don't routinely make prolonged tight turns at low speeds (e.g. looping up or down in a multi-deck parking garage or as in the diagram above).

This noise is relatively common in all autos equipped with LSD and large tires. The LSD clutch packs are there to allow the inner tire to barely rotate, while the outer tire is rotating at a much greater relative rate. In tight turns at higher speeds, the relative difference in wheel rotation between inner and outer tires is minimal.

I wondered what the hell that noise was. I hear it every morning in the parkade because naturally I leave my window open to listen to the V8.

[ersin]

Originally Posted by FifthStreetz

My car doeant have that noise? Should i be concerned? Lol seems like having that noise is a good thing?

This just means you're taking sharp corners too fast. Slow down and maybe you'll hear it.

[gr8000]

I never had the diff noise - my car is a Jun '08 delivery with 15,700km.

As a matter of curiosity, are there any drawbacks when using the diff additive? If for instance will the discs slip smoother after using the additive (thus getting rid of the irritating sound), which could lead to a different LSD performance / behaviour?

[SenorFunkyPants]

Originally Posted by gr8000

As a matter of curiosity, are there any drawbacks when using the diff additive? If for instance will the discs slip smoother after using the additive (thus getting rid of the irritating sound), which could lead to a different LSD performance / behaviour?

Doing anything other than the BMW recommended change of diff oil would not be wise...especially adding aftermarket slip additives.

[LateBraking]

Originally Posted by SenorFunkyPants

Doing anything other than the BMW recommended change of diff oil would not be wise...especially adding aftermarket slip additives.

It's not aftermarket. It's warranty-covered service done at the dealership, using a BMW-created-and-approved additive.

Originally Posted by gr8000

I never had the diff noise - my car is a Jun '08 delivery with 15,700km.

As a matter of curiosity, are there any drawbacks when using the diff additive? If for instance will the discs slip smoother after using the additive (thus getting rid of the irritating sound), which could lead to a different LSD performance / behaviour?

As far as I MYSELF know, there is no change in performance, although you cannot perform differential oil services WITHOUT the additive from the time that you put the additive in.

If you drive it hard (AKA enthusiastically in a demanding, winding road) it should make a rapid ticking sound, like when your body is full of static electricity and you touch something metal over and over. If you drive it slowly in a tight circle with your steering wheel fully locked in a parking lot (or parking structure, the enclosed area will help you hear it) it should make a groaning sound, like the sound that sinking oil tankers make in movies. Try that if you WANT the noise.