We have a lot of correspondence regarding the fitment of limited slip differentials to Z3s, with a lot of information being ambiguous and unreliable.
I found the following table in the BMW TIS disc (2001) providing details of LSD fittings on various models of Z3. Interestingly enough, there is no sign of an LSD being fitted as standard to the larger-engined (2.5, 2.8, and 3.0 litre) non-M models, probably due to the standard ftment of traction control.
The use of a Torsen (torque-sensing) diff on some of the smaller-engined models appears curious, as these can provide a sudden change of torque to the outside wheel while cornering, with sudden oversteer, so giving what many considier to be 'Sports' handling qualities - has any owner of a 'Sports' model noticed this?
The information on the 2.8 was obtained from an equipment list printout by a BMW dealer, in response to the VIN code of my car, which indicated an LSD for all UK 2.8 models.
Please note that many BMW dealers are of the opinion that only the M models of Z3 are fitted with an LSD. ALso note that an LSD can easily be damaged by use of non-LSD oil.
Correct oils are readily obtainable from Opie Oils of Redruth, at approx £12 per litre:
LSD - Castrol SAF-XJ SAE 75-140
Non-LSD - Castrol SAF-XO SAE 75-90
Z3 Final Drive Assignments:
Engine Type
M43 B18 (1.8 114 bhp)
M43 B19 (1.9 117 bhp)
M44 B19 (1.9 138 bhp)
M52 B20 (2.0)
Final Drive Type 168N
From 01.04.98 onwards
cars with sports suspension
also fitted with Torsen diff.
M52 B25 (2.5)
M52 B28 (2.8) LSD
M54 (3.0)
Final Drive Type 188N
S50 (3.2 321 bhp)
Final Drive Type 210
With LSD
S54 (3.2 325 bhp)
Final Drive Type 188
With LSD
Z3 Limited Slip Diff Fitments (Under development)
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Mike Fishwick
- Joined: Fri 19 Jun, 2009 10:27
- Posts: 2094
- Location: Daglan, France
Z3 Limited Slip Diff Fitments (Under development)
Last edited by Anonymous on Sun 12 Aug, 2007 10:25, edited 1 time in total.
s50 differential is type 188 too, s50 and s54 have same differentials.
http://www.realoem.com/bmw/showparts.do ... g=33&fg=05
http://www.realoem.com/bmw/showparts.do ... g=33&fg=05
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Guest
Final Drives
According to the 2001 TIS, they are of different types, and the 2001 ETK shows different part numbers:
S50 - 228 371
S54 - 428 784
Maybe there is a subtle difference in the LSD specification, due to the S54 being fitted with DSC?
S50 - 228 371
S54 - 428 784
Maybe there is a subtle difference in the LSD specification, due to the S54 being fitted with DSC?
Re: Final Drives
Strange, because TIS shows same part numbers for both, 3.15 ratio with type 188 gasket set. But who knows...Mike Fishwick wrote:According to the 2001 TIS, they are of different types, and the 2001 ETK shows different part numbers:
S50 - 228 371
S54 - 428 784
Maybe there is a subtle difference in the LSD specification, due to the S54 being fitted with DSC?
update:
http://www.realoem.com/bmw/showparts.do ... g=33&fg=05
TIS shows that the type 210 is for e36 M3
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Guest
The TIS does not give part numbers - just type numbers - for the final drive, which are different.
The ETK does indeed give the same (188) type number for the gasket set, but that not a part number, and does not mean that the final drives are identical. The part numbers are different, showing that there is a difference between the S50 and S54 final drives.
Perhaps the 210 final drive is a variation on the 188, hence it shares the same gasket set, and allthough the gear ratios are the same, the complete units are different - hence the part number variation.
The ETK does indeed give the same (188) type number for the gasket set, but that not a part number, and does not mean that the final drives are identical. The part numbers are different, showing that there is a difference between the S50 and S54 final drives.
Perhaps the 210 final drive is a variation on the 188, hence it shares the same gasket set, and allthough the gear ratios are the same, the complete units are different - hence the part number variation.
Re: Z3 Limited Slip Diff Fitments
It's the other way round; the clutch pack type LSD as fitted to the M is very aggressive and makes the tail wag whenever the wheels spin up because the take up is sudden. One of the benefits of a Torsen diff is the smoothness of torque distribution.Mike Fishwick wrote: The use of a Torsen (torque-sensing) diff on some of the smaller-engined models appears curious, as these can provide a sudden change of torque to the outside wheel while cornering, with sudden oversteer, so giving what many considier to be 'Sports' handling qualities - has any owner of a 'Sports' model noticed this?
I'm positive my old 2.8 had an LSD of some kind (it's must have been the Torsen type?) as it would spin both wheels up but it didn't suddenly create 30 degree slip angles
and driving the M feels very different under power on/off/cornering.There's also some wrong info on the diff types; all the six cylinder cars use the Type 188 diff, the 210 is E36-based and different to our [E30] diffs (it's must be a mistake relating to the S50 E36 M3?). The smaller engines (4 cylinder z3s) use the type 168 as with the small engined E30s. The S50 and S54 Z3M diffs are identical; this must be a mistake on the "TIS".
The differences between the 188 and 168 are not that big and outwardly they look very similar, the 168 is just an inch or so shorter; but you can easily tell by the number of bolts holding the back plate on (the 188 has 8 bolts and the 168 has 6 bolts). The 168 isn't supposed to be as strong.
The internals of the 188 and 210 are interchangeable though, but the 210 will never fit a Z3 in a million years.
Last edited by c_w on Mon 30 Jul, 2007 16:04, edited 2 times in total.
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Guest
Source?
Not according to the TIS, though - where did you get this information from, Chris?
The TIS specifically refers to the 2.8 and 3 litre models as not being fitted with an LSD, which is understandable as they have ASC anyway. Not many drivers would need both, even if they think they do!
My comments re theTorsen diff were based on an entry in Wikipedia, but this would give a reason for fitting one to the smaller-engined cars - a 1.8 Zed is not likely to need protection from wheel spin, so an LSD which made life more exciting would make a kind of tortured sense.
The TIS specifically refers to the 2.8 and 3 litre models as not being fitted with an LSD, which is understandable as they have ASC anyway. Not many drivers would need both, even if they think they do!
My comments re theTorsen diff were based on an entry in Wikipedia, but this would give a reason for fitting one to the smaller-engined cars - a 1.8 Zed is not likely to need protection from wheel spin, so an LSD which made life more exciting would make a kind of tortured sense.
I think all non-M Z3s have ASC? Inc. the 1.9/1.8s. According to the parts database 2.2s and 3.0s received the Torsen type diff if it was a "Sport" model.
I'm convinced my 2.8 had one as I went to a car handling day at Bruntingthorpe on a skidpan and whilst messing about it would spin round doing a "donut" with both wheels spinning up (watching back on a video).
I reckon BMW didn't fit the ASC traction control to the S50 Z3Ms because it wouldn't work well with the LSD (ie it couldn't react quickly enough to it and would be a waste of time because with ASC on in the wet there always seemed to be a bit of wheelspin before the power cut).
I'm convinced my 2.8 had one as I went to a car handling day at Bruntingthorpe on a skidpan and whilst messing about it would spin round doing a "donut" with both wheels spinning up (watching back on a video).
I reckon BMW didn't fit the ASC traction control to the S50 Z3Ms because it wouldn't work well with the LSD (ie it couldn't react quickly enough to it and would be a waste of time because with ASC on in the wet there always seemed to be a bit of wheelspin before the power cut).
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Guest
LSD Fitments
The ETK lists an LSD for every model ever made, including cars such as the basic 316 saloon, which certainly didn't need one! I think it is just a matter of convenience, as the ETK uses the same headings throughout, even when they are not appropriate. What you get depends on the part number rather than the description. Where in the parts list did you see any reference to a Torsen diff on the 3 litre?
ASC was optional on the smaller-engined Z3 models, and standard on the 2.8 and 3 litre models. As you say, it was not fitted on the S50, as difficulties were found in getting the response time sufficiently low to be worthwhile, an LSD being fitted instead. I remember reading this in a long article on the MR written by one of the deveopment engineers in the BMWCC magazine when it was launched.
I have had both wheels of my Golf GTI spinning well on a slippery track and that certainly didn't have an LSD! On a skid pan with both wheels on equally slippery surfaces, I'm not surprised both your rear wheels were spinning.
If you look on the TIS disc, under Repair Instructions, then Rear Axle, you will find the final drive assignment table, which is where my original info came from. The LSD matter is one which I think will always bring out people who are sure that they were fitted to everything, but this seems to be the only definitive list produced by BMW. With the different oil requirements (SAE 75-140 with an LSD, or 75-90 without) it is obvious that BMW had to provide an authorative list of cars fitted with an LSD for their dealers.
Ther are perhaps a few 2.8 models around with an LSD fitted as a special order, but I have never seen this listed as an option in any of the old brochures. I have read many road tests of the original 2.8 which all state that an LSD is fitted. The same tests also complain that the rear wheels of the Z3 stay too firmly attached to the road, preventing the heroic testers from showing off their ability (?) to control a tail slide, so if an LSD were fitted, its action must have been very subtle!
ASC was optional on the smaller-engined Z3 models, and standard on the 2.8 and 3 litre models. As you say, it was not fitted on the S50, as difficulties were found in getting the response time sufficiently low to be worthwhile, an LSD being fitted instead. I remember reading this in a long article on the MR written by one of the deveopment engineers in the BMWCC magazine when it was launched.
I have had both wheels of my Golf GTI spinning well on a slippery track and that certainly didn't have an LSD! On a skid pan with both wheels on equally slippery surfaces, I'm not surprised both your rear wheels were spinning.
If you look on the TIS disc, under Repair Instructions, then Rear Axle, you will find the final drive assignment table, which is where my original info came from. The LSD matter is one which I think will always bring out people who are sure that they were fitted to everything, but this seems to be the only definitive list produced by BMW. With the different oil requirements (SAE 75-140 with an LSD, or 75-90 without) it is obvious that BMW had to provide an authorative list of cars fitted with an LSD for their dealers.
Ther are perhaps a few 2.8 models around with an LSD fitted as a special order, but I have never seen this listed as an option in any of the old brochures. I have read many road tests of the original 2.8 which all state that an LSD is fitted. The same tests also complain that the rear wheels of the Z3 stay too firmly attached to the road, preventing the heroic testers from showing off their ability (?) to control a tail slide, so if an LSD were fitted, its action must have been very subtle!
ASC(+T) is standard on my 1.9. I certainly did not have to specify it when I ordered the car.
If the sales brochures are to be believed the 2.8 of the time (mine was built 01/99, so the brochures are current at around 10/98) then it came with an LSD as standard equipment.
I haven't got time to check at the mo - I'm away on a course for the next couple of days - but I will check my brochures and give you a direct quote of what it says.
Cheers R.
If the sales brochures are to be believed the 2.8 of the time (mine was built 01/99, so the brochures are current at around 10/98) then it came with an LSD as standard equipment.
I haven't got time to check at the mo - I'm away on a course for the next couple of days - but I will check my brochures and give you a direct quote of what it says.
Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
This lists the various diffs fitted to the 2.2, many have the LSD if an option is ticked. The diff is also slightly different if sports suspension is fitted (not sure why though!). The LSD diffs are type 188 the non-LSD are 168.
http://www.realoem.com/bmw/showparts.do ... g=33&fg=05
I've got a 3.38 LSD in my garage I'll take the back cover off and have a look inside it.
It actually doesn't list an LSD fitted to the 3.0 in the parts list, but I'm sure I've read of the Torsen unit being fitted, even to the automatics somewhere.
http://www.realoem.com/bmw/showparts.do ... g=33&fg=05
I've got a 3.38 LSD in my garage I'll take the back cover off and have a look inside it.
It actually doesn't list an LSD fitted to the 3.0 in the parts list, but I'm sure I've read of the Torsen unit being fitted, even to the automatics somewhere.
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Guest
Real OEM
Yes - Real OEM lists final drives for a 2.2 Z3 with and without the LSD - the choice depending on if the car in question is fitted with Sports suspension or not - as per the Final Drive Assignment chart in the TIS.
Using Real OEM for my 2.8, for example, it gives the non-LSD final drive number (as per the European ETK) and LSD-equipped final drives only for the Tropical, Japan, and Australian markets, with either manual or auto boxes. In other words, it backs up the manual gearbox Final Drive Assignment chart in the TIS.
In spite of this, my 2001 Z3 brochure still lists an LSD as being standard equipment on the 2.8 - but as it says in the small print, the brochure does not consitiute an offer, and is subject to omissions and alterations etc etc!
My October 1998 2.8 final drive does not act as if it carried an LSD, in terms of either turning the wheels when both are free of the ground, or when on mud. snow etc. It will, however, manage to spin both wheels on an averagely smooth road surface
After looking at the pictures in my old Z3 road test book, one can clearly see ASC switches in the 1.9 models! I have however seen a very basic 1.8 Z3 (with narrow steel wheels and cloth seats) which did not have ASC. It is listed as standard fit in 2001 on the 1.8 - for a short time it was then the only sub-2.8 engine available.
I think the answer is that it was, in theory, possible to get an absolutely basic car, but all those normally imported to the UK had ASC fitted as standard, in the same way that most UK-market cars had a higher spec than their much cheaper European cousins - this being used by the manufacturer to justify the much higher price in the UK.
Using Real OEM for my 2.8, for example, it gives the non-LSD final drive number (as per the European ETK) and LSD-equipped final drives only for the Tropical, Japan, and Australian markets, with either manual or auto boxes. In other words, it backs up the manual gearbox Final Drive Assignment chart in the TIS.
In spite of this, my 2001 Z3 brochure still lists an LSD as being standard equipment on the 2.8 - but as it says in the small print, the brochure does not consitiute an offer, and is subject to omissions and alterations etc etc!
My October 1998 2.8 final drive does not act as if it carried an LSD, in terms of either turning the wheels when both are free of the ground, or when on mud. snow etc. It will, however, manage to spin both wheels on an averagely smooth road surface
After looking at the pictures in my old Z3 road test book, one can clearly see ASC switches in the 1.9 models! I have however seen a very basic 1.8 Z3 (with narrow steel wheels and cloth seats) which did not have ASC. It is listed as standard fit in 2001 on the 1.8 - for a short time it was then the only sub-2.8 engine available.
I think the answer is that it was, in theory, possible to get an absolutely basic car, but all those normally imported to the UK had ASC fitted as standard, in the same way that most UK-market cars had a higher spec than their much cheaper European cousins - this being used by the manufacturer to justify the much higher price in the UK.
