====== Z31 Differential Page ======


===== Basic Information =====

All Z31s came with the R200 differential. Keep in mind that during crossover months (September) models may have either the listed ratio or the year prior. It doesn't matter if the car came with a manual or automatic transmission. All that matters is the model year and whether the engine was turbo or not.

===== Stock Gear Ratio =====
84-87 NA = 3.7:1 open\\ 
88-89 NA = 3.9:1 open\\ 
84-86 T = 3.54:1 open\\ 
87-89 T = 3.7:1 clutch LSD *\\ 
88SS = 3.7:1 viscous LSD\\
<sub>* only 87 turbos made after 04/87 had LSD. Before this, they were open differentials. Canada supposedly didn't get LSD until the 88 models.</sub>
\\ \\
According to TSB 87-097:\\
 * A Limited Slip Differential (L.S.D.) is now standard on all 300ZX model vehicles with VG30ET engine (turbo), starting with March 11, 1987 production, VIN number JN1CZ14S1HX152718. This type of differential reduces slippage of the rear wheels and delivers large amounts of traction torque to the wheel that can best utilize it.

===== Fluid Recommendations =====
==== Differential Fluid Levels: ====
R200 - 3-7/8 pt. (approx)\\ 
open diff: API GL-5\\ 
clutch diff: API GL-5 and SAE 80W-90 approved for Nissan LSD

==== Fluid Temperature Ratings: ====
^  temps *  ^  weights  ^
|  below 50<sup>o</sup>F  |  75W  |
|  below 86<sup>o</sup>F  |  80W  |
|  below 104<sup>o</sup>F  |  75W-90\\ 80W-90  |
|  between 14<sup>o</sup>F and 86<sup>o</sup>F  |  85W  |
|  between 32<sup>o</sup>F and 104<sup>o</sup>F  |  90W  |
|  above 50<sup>o</sup>F  |  140W  |
* these are ambient air temperatures 





===== Swap Information =====
Differential swaps are common and very simple. Swapping any non viscous LSD or open diff into any open diff car only requires the differential. Depending on what year your driveshaft and differential are, you may have to swap companion flanges. There are only two differential companion flanges. The 84-86 models have a slightly offset bolt pattern (i.e. make a rectangle). The 87-89 models have a equal bolt pattern (i.e. make a square). Swapping companion flanges usually requires an impact gun. 

Swapping in the viscous LSD from an 88SS model is a bit more intensive. For all models, you will also need the half shafts. For 84-86 models, you will also need to swap the driveshaft companion flange. For non-turbo models, you will also need to swap the outer hubs in the control arms for turbo hubs. 

Also, when swapping differentials, keep in mind that if you change the differential gear ratios, you'll have to change the speedometer pinion gear of your speedometer assembly. It's very simple. Remove the assembly from the transmission. Remove the retaining pin. Replace the gear. Put it all back together.

[[repairs:speedometer|More information]]

===== More Information =====
These differentials are indestructable, change the oil every year or two and you'll never have a problem. Nissan Motorsports sells complete ready to install R200 clutch LSDs for approximately $700-$1100 with your choice of standard R200 ratios.


===== How to tell =====
To tell if you have a limited slip differential, lift both rear tires off the ground and turn 1 wheel. If the opposite wheel turns the same direction then you have a LSD. If not, you have an open diff. The transmission should be in neutral for this.

===== Aftermarket LSD =====
==== Phantom Grip ====
Phantom grip r200 installation procedure is [[http://z31.com/mods/drivetrain/phantomgrip/|here]]. Note: According to some owners, Phantom Grip sucks. Their recommendation is to splurge for an LSD.

==== Real LSD ====
A number of companies make an LSD unit for the R200. Cusco, Quaiffe, Kaaz, NISMO, etc are amoung this list. Look for any company selling an LSD for a 240SX. Since the 240SX models use the R200 as well, the internals are a fairly simple swap. Just have a reputable shop put the differential back together to get the shimming, backlash, etc all correct.


===== Stock LSD Part Numbers =====
^Part Name^  Part number  ^  Price((MSRP retrieved 9/9/09))  ^  QTY  ^
|Carrier|  38421-71S26  |  $915.26|  1  |
|Friction Plate 1.75 mm|  38432-N9000  |  $39.13|  4((Same part of different thicknesses))  |
|Friction Plate 1.85 mm|  38432-N9001  |  $37.33|  4((Same part of different thicknesses))  |
|Friction Disk|  38433-N9000  |  $42.10|  2  |
|Plate Spring|  38435-N3210  |  $37.57|  4  |
|Side Gears|  38423-71S00  |  $109.28|  2   |
|Pinion Gears|  38425-C6000  |  $51.33|  4  |
|Pinion Carrier	|  38427-N9000  |  $140.17|  1  |
|Spacers|  38437-71S00  |  $19.98|  2  |
|Clips|  38225-N3100  |  $1.52|  2  |
|Pressure Rings|  38431-N9000  |  $367.66|  2  |
|Shims by Thickness - Select according to your measurements||||
|2.00mm|  38453-N3100  |  $19.00|  2((Same part of different thicknesses))  |
|2.05mm|  38453-N3101  |  $19.00|  2((Same part of different thicknesses))  |
|2.10mm|  38453-N3102  |  $19.00|  2((Same part of different thicknesses))  |
|2.15mm|  38453-N3103  |  $19.00|  2((Same part of different thicknesses))  |
|2.20mm|  38453-N3104  |  $19.00|  2((Same part of different thicknesses))  |
|2.25mm|  38453-N3105  |  $19.00|  2((Same part of different thicknesses))  |
|Entire LSD Assembly|  38420-71S01  |  $2,303.89|  1  |