Differential Problem

[Redpunk]

Hi Guys,
I purchased a 2007 Z4 M a month ago and at low speed cornering there is a noise coming from Differential.
I went to dealership and they told me that, nobody change the Diff. Fluid before and that's why it is causing the problem.
They changed the diff. fluid and told me drive little bit and see if there is any noise again.
The fluid reduced the noise, but not whole a lot.
Dealership quote me with $2700 + Tax for a Differential and $1100 for labor.
Should I purchased a Oem Differential or go with an aftermarket one?
Do you guys know any good aftermarket Differential that I can upgrade?
I am a newbie for BMW's, so I need a good advice.
Thank you very much for your time.

[ebruder]

A very simple question. Is the car still under warranty?

EB

[RBull]

^may not matter if service records can't be found for diff change.

[Redpunk]

Originally Posted by ebruder

A very simple question. Is the car still under warranty?

EB

No, it is not under warranty anymore.

That's why I am asking, If there is an other aftermarket option to solve this problem.

I was googling and found www.enthusiastauto.com rebuild Differentials, such as 3.46 / 3.64 / 3.91 / 4.10

Is there anybody, send their differential to this company?

[nmulax]

First Z4M I've heard of that the differential already is going on. Ask to speak with the Service Manager (not just a Service Associate) and ask about a goodwill repair - or see if he'd be willing to split the cost.

[AWM3]

I would try a few different brands of limited slip fluid before buying a new differential. The friction modifiers are different in various brands which affects the behavior of the LSD clutches, which is the noise you are hearing. 2 quarts of gear oil is a lot cheaper than a new differential.

This is the product that I use which works well in my car:

http://www.turnermotorsport.com/html...DUCT_ID=75/140

[dekaliber]

OP, can you describe the noises that you're hearing? Is is consistently reproducible? I'm getting some intermittent noises from the rear of the car and am wondering if it might be the diff. I can't seem to always get it to happen though.

Was the 1200 mile service not done on your car?

[jmillet]

Originally Posted by Redpunk

Hi Guys,
I purchased a 2007 Z4 M a month ago and at low speed cornering there is a noise coming from Differential.
I went to dealership and they told me that, nobody change the Diff. Fluid before and that's why it is causing the problem.
They changed the diff. fluid and told me drive little bit and see if there is any noise again.
The fluid reduced the noise, but not whole a lot.
Dealership quote me with $2700 + Tax for a Differential and $1100 for labor.
Should I purchased a Oem Differential or go with an aftermarket one?
Do you guys know any good aftermarket Differential that I can upgrade?
I am a newbie for BMW's, so I need a good advice.
Thank you very much for your time.

SIB 33 01 02 applicable to the E85/86 addresses the situation of a grinding noise coming from the differential during slow cornering. This noise is best heard during tight cornering situations for example parallel parking, driving in a tight circle, etc.
The correction is the differential oil should be replaced with specially formulated differential oil, P/N 83 22 2 282 583, SAF-XJ plus FM Booster. That part number gets you 500ml at MSRP $30.93.

[Redpunk]

Originally Posted by jmillet

SIB 33 01 02 applicable to the E85/86 addresses the situation of a grinding noise coming from the differential during slow cornering. This noise is best heard during tight cornering situations for example parallel parking, driving in a tight circle, etc.
The correction is the differential oil should be replaced with specially formulated differential oil, P/N 83 22 2 282 583, SAF-XJ plus FM Booster. That part number gets you 500ml at MSRP $30.93.

Thanks for a great info.

They changed the differential oil, same part number that u gave me.

But there is still a grinding noise, while I am in the parking lot, turning right and left.

I really don't want to waste a lot of money on this, If I really dont need.

But the grinding noise is so annoying.

I am going to a Tuning Shop (BMW Specialist) tomorrow and let them check the car, so he could give me a better solution than stealership.

[Redpunk]

Originally Posted by car62

I would try a few different brands of limited slip fluid before buying a new differential. The friction modifiers are different in various brands which affects the behavior of the LSD clutches, which is the noise you are hearing. 2 quarts of gear oil is a lot cheaper than a new differential.

This is the product that I use which works well in my car:

http://www.turnermotorsport.com/html...DUCT_ID=75/140

Did you also have this grinding noise, before you change the diff. oil?

[CFoote]

Redpunk, I hate to advertise my parts given your expensive problem, but I do have a 3.91 Ring & Pinion that would fit perfectly in your car for $650. Installation would be about $1000 and you'd get a great performance boost.

Regardless of what you do, be sure you go to someone who specialies in differentials, they have very very tight tolerances and if someone doesn't know what they are doing things can get worse.

Chris

[AWM3]

Rebuilt differentials tend to fail with alarming frequency. If you can find a low mileage original unit from a recycler that would be a better option. The basic unit is sound and should last for over 100K miles in normal use.