E36 M42 Diff Gear Swap

I need to replace differential gear for 1992 BMW E36 M42 engine as it makes
noise.

1. Is that true that the ratio of this stock final drive is 3.45?

2. Will 1996 328 E36 differential gear with 3.91 ratio fit my BMW?

3. If I could swap with this final drive, will this improve the
acceleration?

Thank guys,
Kevin

On Fri, 24 Aug 2007 00:18:25 GMT, "Brewer" > wrote:

>I need to replace differential gear for 1992 BMW E36 M42 engine as it makes
>noise.
>
>1. Is that true that the ratio of this stock final drive is 3.45?
>
>2. Will 1996 328 E36 differential gear with 3.91 ratio fit my BMW?
>
>3. If I could swap with this final drive, will this improve the
>acceleration?
>
>Thank guys,
>Kevin
>
If it fits then Yes acceleration will be quicker but fuel consumption will also
increase - less MPG.

Perhaps these numbers might help:

92 - E36 M42 1.8lit. 3.45:1 - 33 10 1 214 845

96 328i 3.07:1 - 33 10 1 214 631

96 328i 2.93:1 - 33 10 1 214 636

96 328i MALAYSIA ONLY - 3.91:1 - 33 10 1 428 387

So if you can get hold of a Malaysian 328i and steal the rear end .....?

However, I would imagine they will all fit but it appears the 3.9 wasn't an
option in the US or Euroland.

Hugh
Sir Hugh of Bognor

--
I used to be an Egotistical Meglomaniac - but now I'm just perfect!

Hugh Gundersen


Bognor Regis, W.Sussex, England, UK

On Aug 24, 9:09 am, wrote:

> However, I would imagine they will all fit but it appears the 3.9 wasn't an
> option in the US or Euroland.
>


I'm not sure if the mounting is different so you might also need the
subframe/diff carrier.

On Fri, 24 Aug 2007 04:56:03 -0700, adder1969 > wrote:

>On Aug 24, 9:09 am, wrote:
>
>> However, I would imagine they will all fit but it appears the 3.9 wasn't an
>> option in the US or Euroland.
>>
>
>
>I'm not sure if the mounting is different so you might also need the
>subframe/diff carrier.

Parts list pictures look the same but then that's just a drawing although they
are usually fairly accurate.
Sir Hugh of Bognor

--
I used to be an Egotistical Meglomaniac - but now I'm just perfect!

Hugh Gundersen


Bognor Regis, W.Sussex, England, UK

> I need to replace differential gear for 1992 BMW E36 M42 engine as it makes
> noise.
>
> 1. Is that true that the ratio of this stock final drive is 3.45?

Yes. 325i was 3.15:1

> 2. Will 1996 328 E36 differential gear with 3.91 ratio fit my BMW?

Ar you sure it's 3.91:1? I don't think it is.

> 3. If I could swap with this final drive, will this improve the
> acceleration?

Yes, if it's IS 3.91:1. But at the expense of much higher rpms when
cruising at speed and a lower top speed. It's not a good idea.

--
Who needs a life when you've got Unix? :-)
Email: , John G.Burns B.Eng, Bonny Scotland
Web : http://www.unixnerd.demon.co.uk - The Ultimate BMW Homepage!
Need Sun or HP Unix kit? http://www.unixnerd.demon.co.uk/unix.html
www.Strathspey.co.uk - Quality Binoculars at a Sensible price

On Sat, 25 Aug 2007 11:43:52 +0100, John Burns >
wrote:

>> I need to replace differential gear for 1992 BMW E36 M42 engine as it makes
>> noise.
>>
>> 1. Is that true that the ratio of this stock final drive is 3.45?
>
>Yes. 325i was 3.15:1

Wasn't the M42 engine an 1800cc ??????
>
>> 2. Will 1996 328 E36 differential gear with 3.91 ratio fit my BMW?
>
>Ar you sure it's 3.91:1? I don't think it is.

No it isn't John - apparently the 3.91 was only a Malaysian option???
No doubt one could order it as an option for towing a caravan with the 1800 but
I bet nobody did.
>
>> 3. If I could swap with this final drive, will this improve the
>> acceleration?
>
>Yes, if it's IS 3.91:1. But at the expense of much higher rpms when
>cruising at speed and a lower top speed. It's not a good idea.

Especially at petrol prices as they are today and will be tomorrow and the day
after.....................
Sir Hugh of Bognor

--
I used to be an Egotistical Meglomaniac - but now I'm just perfect!

Hugh Gundersen


Bognor Regis, W.Sussex, England, UK

Yes it does appear from Real OEM that your '92 318i has a 3.45 differential
if you have a manual or (4.44 if you have an automatic transmission). Yes
the 3.91 differential from a '96 328i automatic will bolt into your car OK
and you will probably be pleased with the performance since the e30 318is
with the same engine used a 4.10 differential.
http://www.realoem.com/bmw/showparts...& hg=33&fg=05

> wrote in message
...
> On Sat, 25 Aug 2007 11:43:52 +0100, John Burns >
> wrote:
>
>>> I need to replace differential gear for 1992 BMW E36 M42 engine as it
>>> makes
>>> noise.
>>>
>>> 1. Is that true that the ratio of this stock final drive is 3.45?
>>
>>Yes. 325i was 3.15:1
>
> Wasn't the M42 engine an 1800cc ??????
>>
>>> 2. Will 1996 328 E36 differential gear with 3.91 ratio fit my BMW?
>>
>>Ar you sure it's 3.91:1? I don't think it is.
>
> No it isn't John - apparently the 3.91 was only a Malaysian option???
> No doubt one could order it as an option for towing a caravan with the
> 1800 but
> I bet nobody did.
>>
>>> 3. If I could swap with this final drive, will this improve the
>>> acceleration?
>>
>>Yes, if it's IS 3.91:1. But at the expense of much higher rpms when
>>cruising at speed and a lower top speed. It's not a good idea.
>
> Especially at petrol prices as they are today and will be tomorrow and the
> day
> after.....................
> Sir Hugh of Bognor
>
> --
> I used to be an Egotistical Meglomaniac - but now I'm just perfect!
>
> Hugh Gundersen
>
>
> Bognor Regis, W.Sussex, England, UK
>

Brewer wrote:
> I need to replace differential gear for 1992 BMW E36 M42 engine as it makes
> noise.
>
> 1. Is that true that the ratio of this stock final drive is 3.45?
>
> 2. Will 1996 328 E36 differential gear with 3.91 ratio fit my BMW?
>
> 3. If I could swap with this final drive, will this improve the
> acceleration?
>
> Thank guys,
> Kevin
>
>

Kevin,

Are you sure you need to do this? My '95 325i has whined under a light
load since the day I got it used with ~60k miles. It now has more than
twice that and I have done nothing to the rear end except change the
gear oil.

As to your questions above, I cannot answer the first two questions.
But if both 1 and 2 are correct, then the answer to 3 is Yes.


--
-Fred W

"Jack" > wrote in message
news:n82Ai.264$Ah3.40@trndny04...
> Yes it does appear from Real OEM that your '92 318i has a 3.45
> differential if you have a manual or (4.44 if you have an automatic
> transmission). Yes the 3.91 differential from a '96 328i automatic will
> bolt into your car OK and you will probably be pleased with the
> performance since the e30 318is with the same engine used a 4.10
> differential.
> http://www.realoem.com/bmw/showparts...& hg=33&fg=05

He might be please with the acceleration, but I doubt he will be pleased
with the reduced top speed, increased fuel consumption, high rev's when
cruising and reduced life expectancy of the engine.

If the car is auto then he may confuse the engine and gearbox management.

>
> > wrote in message
> ...
>> On Sat, 25 Aug 2007 11:43:52 +0100, John Burns
>> >
>> wrote:
>>
>>>> I need to replace differential gear for 1992 BMW E36 M42 engine as it
>>>> makes
>>>> noise.
>>>>
>>>> 1. Is that true that the ratio of this stock final drive is 3.45?
>>>
>>>Yes. 325i was 3.15:1
>>
>> Wasn't the M42 engine an 1800cc ??????
>>>
>>>> 2. Will 1996 328 E36 differential gear with 3.91 ratio fit my BMW?
>>>
>>>Ar you sure it's 3.91:1? I don't think it is.
>>
>> No it isn't John - apparently the 3.91 was only a Malaysian option???
>> No doubt one could order it as an option for towing a caravan with the
>> 1800 but
>> I bet nobody did.
>>>
>>>> 3. If I could swap with this final drive, will this improve the
>>>> acceleration?
>>>
>>>Yes, if it's IS 3.91:1. But at the expense of much higher rpms when
>>>cruising at speed and a lower top speed. It's not a good idea.
>>
>> Especially at petrol prices as they are today and will be tomorrow and
>> the day
>> after.....................
>> Sir Hugh of Bognor
>>
>> --
>> I used to be an Egotistical Meglomaniac - but now I'm just perfect!
>>
>> Hugh Gundersen
>>
>>
>> Bognor Regis, W.Sussex, England, UK
>>
>
>