Rear Differential

[the eldest boy]

Hey guys, i wonder if someone can help me out...i got a load of problems with the car and i need some ideas urgently!

I have already paid 5,000aed for AGMC to service the car. I am about to pay 7,000aed to X Service for repairs they have carried out aginst the defects identified at the service. Though i am not thrilled about the 12,000aed price tag for this work, it's not the end of the world.

However, X service have been working to identify the source of a gringing noise coming from the rear of my car upon turning. After much investigation, they have said that the rear diff needs replacing, at a cost of 15,700aed.

I know X Service aren't ripping me off, but i need to investigate all avenues before i commit to that cost. So, does any know where i can source a new or used rear differential for my 2004 E46 M3? Are there any local or international suppliers, spare parts dealers or breakers yards that might have one going cheap?

There are some listed on ebay in the UK, but i'm not sure what i'm looking for. They are certainly cheaper than the prices here, but am i getting the right thing? Does it make a difference for left/righ hand drive cars or is the diff universal? Are the below parts suitable? Any help VERY much appreciated.

http://shop.ebay.co.uk/?_from=R40&_t...All-Categories

Phil

[SSense]

Phil... after reading your about your problem it reminds me exactly of the same problem i had with my E39 M5.. The grinding noise used to occur only on turns, therefore i took the car to the dealer and without asking them to diagnose what the fault is I asked them to change my differential oil.. Once that was done, the noise disappeared after around 2 days of driving.
This grinding noise occurs when there is no differential oil and its dry..

Good Luck !

[Bruno]

have you changed the diff oil?

[Haissam]

it's 99% the diff oil, had the same problem with my Z4M the minute i drove out from the showroom, and then AGMC replaced it under warranty..

that's not the first time X-Service ask to replace the diff (happened with another member here) but go to them & tell them you want to change the oil first.. if it doesn't work then u got no other choice

[Ayham]

Same problem here too 3 months ago: I changed my differential bushings and filled up the diff housing with oil.

Do you have any shaking when applying the throttle suddenly? Do you hear any violent banging noise from the rear when shifting gears?

[Wazif]

SAF-XJ + FM Booster, bmw part number - 83222282583

that the oil u r looking for. Available in AGMC.

[Wazif]

Ayham, the shaking when applying the throttle and the banging noise during shifting are all causes of the Diff bushings right?

I remember this had happend to the club car after HPDS ;)

[SSense]

SAF-XJ + FM Booster, bmw part number - 83222282583

that the oil u r looking for. Available in AGMC.

They dont sell the oil in quarts, you have to get it changed with them..

[Ayham]

Ayham, the shaking when applying the throttle and the banging noise during shifting are all causes of the Diff bushings right?

I remember this had happend to the club car after HPDS ;)

Yup...The diff was broken after HPDS R1 along with its housing bushings.

[Wazif]

They dont sell the oil in quarts, you have to get it changed with them..

nope ...they do sell them in quarts...i bought them myself.... :)

[SewerSideUp]

There you go, it's just a matter of oils so far. Change them and check.
Keep this as a rule of thumb, make sure youve done ALL the servicing and consumable replacements BEFORE you jump into replacing major parts. It'll save you alot !

[the eldest boy]

Thanks so much for your responses guys, i knew this was the place to come for great advice.

I know that X have done some checks and tests but as i am not technically minded i can't say whether or not they have tried the measure you suggest below. Maybe Shaq X could offer some advice if he reads this thread?

I have spoken to some parts suppliers in Sharjah an i have a potential lead on a used differntial, which if it's suitable and working i will investigate further. I'm guessing that a substantial part of the 16,000 cost is the part itself, which i assume is purchased from AGMC, so if i can get a used part the price should come down substantially. I need to confirm with X exactly what (if the other measures do not solve the problem) parts need replacing and take that information to suppliers to get prices.

X said that diff failure is common on M3's, but is it that simple? I know it's guess work, but what might have happened to cause such a massive failure to such an expensive part? Why are car companies not addressing what are considered to be "known weaknesses" or "design faults" on their vehicles?

Thanks again guys, you're the best :bow:

[Ayham]

BMW diffs are the closest thing to sheer rocks!!! I've tracked and raced my M3 and the previous owner did worse things to it and the diff is as good as new. BMW KNOWS LSD! Period.

In short, I have come across an example or two regarding damaged LSD units on BMWs. With stock power figures, they're way over designed!

If you want, I can take a spin in your car tonight and compare if it's displaying the typical syndromes or not....

[alquazi]

I would check with central parts for the price of a new one. Know that will help you in case you need to buy/find a used one.

[SewerSideUp]

Most people know of engine and gearbox oil, some are lucky enough to know theres power steering fluid. The pro's know of such things as brake oil and differential oil !

Some cars come out of the factory and get used for years and years without having their differntial cover unbolted once! That is a fact.

BMW differentials, especially M LSD's are the best around. Some LSD have been around for 20 years and are still running strong !

Main point is, most owners do not replace the differential oil at all. Imagine your diff's been running on the same stuff since 2004 ? In this heat!!
That is most probably your case.

Preventative maintanence is better than repairs, you can bet on that !