# BMW - Rear differential gone (!)



## Plek Trum (6 Jul 2009)

So bad news..
turns out the rear differential is gone on my 00 BMW 316iSE.
My dealership has advised that it would be very expensive to replace (even if I sourced a second hand one) and given the uear of the car, its not worth doing.

Two questions:
(1) What exactly IS the rear differential (I know, I should have asked more questions... dealership is not nearby, relative collecting car for me)

(2)  Is this as big a job as they say?

(3) Is it safe to drive?

I would really *really* appreciate all opinions and advice on this, bad time for my car to go!


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## Padraigb (6 Jul 2009)

1. It's a clever piece of gearing that allows the wheels rotate at different speeds when the car is not travelling in a straight line.
2. I would expect so.
3. Not very!

Sorry, I would tend to agree with your dealer.


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## mathepac (6 Jul 2009)

1. All you ever wanted to now about E46 diffs and changing them, complete with pictures, US prices and DIY guides - http://bokchoys.com/differential/index.htm
2. Not for the DIYer
3. No.

Is the dealer absolutely certain that its the actual diff that's gone? (this is an unusual problem and is very expensive to fix)

A much more common problem (as I discovered after a bit of research) is that the  differential mounts fail which can cause the diff, the drive-shaft and half-shafts leading from the diff to rattle around disconcertingly. This is awkward to do, but would only cost a fraction of the other job. If you know someone who is comfortable (and safe) rooting around under the rear-end of an E46, it might be worthwhile asking them to take a look.

Have a read of this complete 'how to' guide with part-numbers for the mounts only etc http://forum.e46fanatics.com/showthread.php?p=6910121

HTH


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## Plek Trum (7 Jul 2009)

Mathepac - thank you so very much for the info and links, I'll definately have a browse and will take the car for a second opinion just to be sure. Appreciate the posting, hopefully might throw up a few options for me.  Will let you know!


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## Eng Car 1 (7 Jul 2009)

Might be woth trying a few of the smaller well rated independant BMW garages. Have no first hand exp of them but they seem to be well regarded on BMW owners forums


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## onq (7 Jul 2009)

Before making an assessment of the problem yourself, but having armed yourself with the information posted here, perhaps you might consider getting an engineer to look the car over?

This may help you identify your particular model since it seems two were current in the year 2000:

http://en.wikipedia.org/wiki/BMW_3_Series


5 E36, 1991-2000
6 E46, 1998-2005

I've never heard of a BMW diff going [I don't drive one] and yours was the only hit I got on the first page by googling it as 

00 BMW 316iSE differential

Googlong 

BMW differential 

got loads of results.



You might get better info amongst them but the following is for an earlier model and is writtne in American [foot-ponds, etc ]

http://www.bimmerdiy.com/diy/e36diffswap/

From the pics you'll see you need the use of a workshop a raised lifter for the car and proper tools.

For my money, before you start you should have done heavy work on cars before as there are techniques before you even approach the work.

You need to prepare - older models underbody work starts with pre-cleaning everything to get the light muck off and then careful work to remove corrosions and ease fasteners [nuts, bolts, clips] that may be rusted in place or siezed through electrolytic corrosion.

You'll need the help an experienced back street mechanic to do things in a way that won't result in a long replacement parts bill!

You will also need to bidget for the time to do this.
What may take a day on a recent model in good nick might take two or three days on an older model with siezed threads and rusted underbody sections.
Plus you'll need time to identify, remove and source replacements for any gaiters or seals you remove as they will probably not be re-usable.

Take heed of the disclaimer at the bottom of the page I or which I gave the link.

_"Do this procedure at your own risk. Follow manufacturer's guidelines and specifications. If in doubt of your abilities, please leave this to a professional."_

Remember that this is a critical component in your car, and any final assessment, assembly checking and preparation, and final placement work should be undertaken by an experienced mechanic, not you, particularly final fixing and pre-loading of bolts and nuts.

Ideally he should sign off on the work.

Let me put it like this.

I repaired my own bikes for years and kept them serviced.
I've helped people replace engines in cars.
I know a lot about guntering.

I wouldn'y touch diff work.

ONQ.


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## Plek Trum (8 Jul 2009)

Thanks for all replies- have a BMW mechanic doing a favour for me at a garage he has use of on the side (weekends / evenings).  Worth a shot, have located replacement part so its minimal cost to what was quoted at main dealers (more than 75% cheaper).  If it works all well and good - if not I guess Im in the market for a new car.  Will post results here next week (hopefully positive!)


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## Plek Trum (14 Jul 2009)

Just an update...

Got the rear diff replaced on a recommendation of a colleague.  Small independent garage with BMW trained mechanic.  Price (inlcuding the actual part, labour and VAT) *360euro!*
Extremely happy and the car is drving like a dream - even better than it had been previously.  Top service, all certified and warranty given.  Like a new car!

I cannot tell you what a relief it is and how delighted I am with the work.  If anyone needs a recommendation (Kerry), please feel free to PM me for details.

_(360 euro is a *big *difference compared to the 1800 quoted by main dealer!)_


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## mathepac (14 Jul 2009)

Thanks for the update, mighty stuff, great outcome.


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## Ninagun (26 Sep 2017)

Hey. I just bought a Cat D salvage car and the primary problem is the rear ended. Can you please refer me to your mate to get it fixed?


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