View source for Limited Slip Differential

Limited Slip Differentials are referred to as a Slipper or as an LSD. This contrasts to the normal [[Differential|differential]] fitted that is known as an Open Diff.

LSDs were fitted as standard to the [[325i_Sport|325i Sport]] and [[M3]]. They were ''not'' standard on the [[318iS]], but were on option available to all [[:Category:E30_Range|E30 models]].
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=Case sizes=

E30s had two differential case sizes, which are interchangeable and the same width but will require adjustment of the [[Drivetrain#Propshaft|propshaft]]. Learn more about [[Fitting_an_E30_Differential|fitting a differential]].

E30s used either a Small Case or Medium Case differential. Other models used a Large Case which is not directly interchangeable but the internals can be swapped.

=Ratios=

Below is a list of ratio and cars in which they can be found.

* 3.15 - M3
* 3.64 - prefacelft 325i
* 3.73 - facelift 325i
* 3.91 - facelift 325i touring, cabrio, 325i with getrag 260 sport
* 4.10 - found optionally on UK spec 318i/318iS 2/4dr in Small Case, and on all US M3 models in Medium Case.
* 4.27 -
* 4.44 - 

For more info on these numbers, learn more about [[Differential|differentials]].

=Identification=

To identify an LSD one can first check for the presence of the tag on the rear casing. The ratio on this will be prefixed with an S for LSDs.

Alternatively one can jack up one rear wheel, ensure the car is out of gear and hand-brake is off then turn the raised wheel. Resistance on that wheel would usually indicate an LSD. An alternative method is to try to leave skid-marks pulling away on good tarmac, two tyre marks for more than a few inches would indicate a properly "locking" LSD. This won't work so well on grass or gravel as on loose surfaces both wheels can slip easier even for non-limited slip differential types.

=Oil=

E30 LSDs are clutch plate type and require [[Oil#Differential|special oil]]. The BMW recommended oil is Castrol SAF-XJ

[[Category: Technical]]
[[Category: Drivetrain]]
[[Category: Differential]]