Diff fluid change

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TomH84
Joined: Sun 15 Dec, 2013 15:22
Posts: 113

  Z3 roadster 2.2i

Diff fluid change

Post by TomH84 »

Just back from 2 weeks in France - great driving (pics to follow). The little Zed drove perfectly and racked up 2200 miles with ease.

The only little 'niggle' I had was with the diff. It was a little whiny at times - nothing dramatic, but I think it's time for a fluid change. Don't think it's been done.

After searching old posts, I'm set to go with CASTROL SYNTRAX LIMITED SLIP 75W-140 (x2 i litre bottles). My car is a late '02 2.2 M54 engine. The rear drive is 188N i think. Sound alright?

Searching for diff oil in the old posts and online just confused me... Way too much info!

Cheers all,

Tom
2002 BMW Z3 2.2i 82k
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1971(K) MGB GT - the 'other' car
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Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Diff fluid change

Post by Del »

Maximum protection additives GL5 gear oil
75W-90 if no limited slip diff
75W-140 if Limited slip diff fitted
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lightning
Joined: Tue 27 Nov, 2007 08:15
Posts: 818

  Z3 roadster 3.0i
Location: Stockport

Re: Diff fluid change

Post by lightning »

I investigated this as well.

My conclusions were, as above.
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TomH84
Joined: Sun 15 Dec, 2013 15:22
Posts: 113

  Z3 roadster 2.2i

Re: Diff fluid change

Post by TomH84 »

Thanks guys!

I've entered my VIN online and there's no mention of a LSD in the print out (I assume it would be listed as an optional extra?).
Does this mean I'm non-LSD - therefore need the 75/90w?

Cheers,

Tom
2002 BMW Z3 2.2i 82k
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1971(K) MGB GT - the 'other' car
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Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Diff fluid change

Post by Del »

The attached link shows stuff fitted to the cars. There is the "standard equipment list" and "optional extra list" - but both are items actually fitted to your car. It does not list items which were generally available but not fitted to your car.

I haven't got a LSD on my 1.9 diff and it took almost 1 litre of 75W-90.

http://www.bmwarchive.org/vin/bmw-vin-decoder.html
pedro20001
Joined: Sat 29 Jan, 2011 20:34
Posts: 361

  Z3 roadster 2.2i
Location: tamworth

Re: Diff fluid change

Post by pedro20001 »

Is it a sport, if so it will have a lsd
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TomH84
Joined: Sun 15 Dec, 2013 15:22
Posts: 113

  Z3 roadster 2.2i

Re: Diff fluid change

Post by TomH84 »

It's not a sport and there's also no mention of any LSD option when you check the VIN, so it must be non-LSD and thus 75/90w. Part of me is still tempted to go with 75/140w, if only because it's specified as non-LSD safe too. Insurance policy too. Hmm.

Thanks!
2002 BMW Z3 2.2i 82k
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1971(K) MGB GT - the 'other' car
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lightning
Joined: Tue 27 Nov, 2007 08:15
Posts: 818

  Z3 roadster 3.0i
Location: Stockport

Re: Diff fluid change

Post by lightning »

You could always try the following.

Jack up both rear wheels. With the car in neutral, turn one rear wheel by hand. If the other one turns the same way you have an LSD. If it turns in the opposite direction you don't have an LSD.

EDIT does not work on "torsen" limited slip diffs in Z3's.....so ignore my useless "advice"
Last edited by lightning on Fri 18 Jul, 2014 17:15, edited 3 times in total.
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

Re: Diff fluid change

Post by Mike Fishwick »

The LSD oil used to be Castrol SAF-XJ, but it is now one of the Syntrax range.

The LSD is listed as a 'Sperredifferential 25%' in the specification sheet. All UK - market Z3s seem to have been equipped with an LSD, as distinct fom Japan, for example, which were not.

Your 2.2 would have been fitted with a Torsen LSD, which behaves like a non-LSD final drive until a torque imbalance is sensed, when it progressively transfers drive from one side tothe other, soit is no use jacking it up and turning the wheels - my October 1998 2.8 has an LSD, and behaves like a non-LSD final drive, the Torsen LSD seeming to have been fitted fom September 1998.

The 'Sport' cars had an LSd, but were merely a cosmetic exercise, similar to the 'Orinoco' cars - there was nothing unusual about them apart frm a tiny front spoiler lip, even though some motoring hacks copied the BMW press release word for word, which stated they were equipped with an LSD - which was truejust like any other UK Market Z3! The press release even claimed that the front anti roll bar imparted an anti-dive characteristic to the suspension, which showed that the writer did not know how an ARB works!
Last edited by Mike Fishwick on Fri 18 Jul, 2014 10:40, edited 1 time in total.
A Z3 is not just for Christmas - it's for life!
Cooper01
Joined: Tue 29 Apr, 2014 08:06
Posts: 163

  Z3 roadster 3.0i

Re: Diff fluid change

Post by Cooper01 »

Hi, just to clarify.... can we use the LSD 75W-140 if we are unsure? Really, it won't make any difference will it?
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

Re: Diff fluid change

Post by Mike Fishwick »

I would not think it woud be a problem - but why not find out if your car does have an LSD? It is easy enough to do so.
A Z3 is not just for Christmas - it's for life!
Cooper01
Joined: Tue 29 Apr, 2014 08:06
Posts: 163

  Z3 roadster 3.0i

Re: Diff fluid change

Post by Cooper01 »

Thanks Mike, I was watching out of interest.
My car does not have a LSD according to the VIN decoder but this comment confused me;

Your 2.2 would have been fitted with a Torsen LSD, which behaves like a non-LSD final drive until a torque imbalance is sensed, when it progressively transfers drive from one side tothe other, soit is no use jacking it up and turning the wheels - my October 1998 2.8 has an LSD, and behaves like a non-LSD final drive, the Torsen LSD seeming to have been fitted fom September 1998.

I am easily confused! :roll:

Cooper
Mike Fishwick
Joined: Fri 19 Jun, 2009 10:27
Posts: 2093

  Z3 roadster 2.8
Location: Daglan, France

Re: Diff fluid change

Post by Mike Fishwick »

I would suggest that you check with any dealer to get a free copy of your car's specification sheet - I have found so many errors on internet and or American websites that I automatically discount them now.
A Z3 is not just for Christmas - it's for life!
Cooper01
Joined: Tue 29 Apr, 2014 08:06
Posts: 163

  Z3 roadster 3.0i

Re: Diff fluid change

Post by Cooper01 »

Mike Fishwick wrote:I would suggest that you check with any dealer to get a free copy of your car's specification sheet - I have found so many errors on internet and or American websites that I automatically discount them now.
One again, thanks Mike. I will do that very soon and pass the message on!
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c_w
Joined: Thu 19 Aug, 2004 16:50
Posts: 4032

  M roadster S50

Re: Diff fluid change

Post by c_w »

The Torsen diffs can be quite clunky on initial drive take up due to the amount of gears inside which might be partly why there are so many complaints about noises on clutch take up!

I have always understood that the mechanical Torsen diff doesn't need 75-140, that is for the plate style LSD and the other LSDs fitted to newer M cars. It is essentially a very durable oil that works in very high temps (the clutch plate type diff in the M gets a lot hotter by design). It also has additives that were added to quieten the plates in low speed turning conditions (like parking). Lost of E46 M3 owners complained about this so BMW revised it I think. The Castrol 75-140 oil is also recommended for GTR diffs too which will be a very different design but it is an example that the properties of the oil are for very hard use/hot conditons.

That said I would say use 75-140 for either diff, it won't harm an open diff or a Torsen.
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lightning
Joined: Tue 27 Nov, 2007 08:15
Posts: 818

  Z3 roadster 3.0i
Location: Stockport

Re: Diff fluid change

Post by lightning »

If you do use the wrong oil, will the resulting catastrophic failure be contained within the differential casing, or will it scatter its internals down the middle of the road?
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