A Limited Slip Differential (LSD) prevents one of the rear wheels slipping. A differential is inside the final drive (ring & pinion) gears and allows the left and right wheels to turn at different speeds. This is important of course for going around corners. The downside is that if one wheel is on slippery ground (ice, gravel, mud, etc) the car doesn't go at all, as one wheel is turning but slipping and the other not turning at all. Hence the usefulness of LSD or locking diffentials, which are typically used on high-performance cars. Locking is typically used on off-road vehicles, LSD for road vehicles, including racecars. Most productions cars did not and still do not come equipped with LSD. Less expensive cars (like the 1200) did not even have it as an option, however Datsun Competition sold an LSD that fit Datsun 1200.
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Overview
Limited Slip Differentials come in many different types, but the main thing is they limit wheelspin. This is useful in racing and in low-traction surfaces (rain, snow, etc). Or for maximum accleration at full throttle. Different types of LSD are cone-clutch, spring-loaded, clutch-pack, hydrodynamic (viscous), etc. Some trademarks are "Posi-Traction" (GM), "Traction-Lok" (Ford), Torsen (Bosch).
A differential is inside the "final drive" (ring & pinion) gears and allows the left and right wheels to turn at different speeds. This is important of course for going around corners. The downside is that if one wheel is on slippery ground (ice, gravel, mud, etc) the car doesn't go at all, as one wheel is turning but slipping and the other not turning at all. Hence the usefulness of LSD or locking diffentials, which are typically used on high-performance cars. Locking is typically used on off-road vehicles, LSD for road vehicles, including racecars.
LSD
Nissan Performance racing parts used to sell a clutch-pack type LSD for the H145, H150 and H165. These parts are NLA, however may be found occasionally in specialty shops or on eBay.
H145
LOM58
Nissan Performance racing parts used to sell an LSD for the 1200 -- H145 LSD (NLA)
Nissan Part Number: 38420-H1020 L/S ASSY H145 (TO 8/74)
Parts
From the 1984 Nissan Competition Catalog:
H145A LIMITED-SLIP ASSY (TO 8/74) * 38420-H1020 L/S ASSY * 38423-H0120 SIDE GEAR (2) * 38424-H0120 THRUST WASHER (1.0MM) (2) * 38424-H0120 THRUST WASHER (1.25MM) (2) * 38425-H0120 PINION (4) * 38427-H0120 PINION MATE SHAFT * 38429-H0120 PINION SHAFT * 38430-H0120 DISTANCE PIECE * 38431-H0120 PRESSURE RING (2) * 38437-H0120 CENTER RING * 38432-H0120 FRICTION PLATE (1.5MM) (2) * 38432-H0121 FRICTION PLATE (1.45MM) (2) * 38432-H0121 FRICTION PLATE (1.55MM) (2) * 38433-H0120 FRICTION DISC (1.5MM) (2) * 38434-H0120 SPRING DISC (1.5MM) (2) * 38435-H0120 SPRING PLATE (1.5MM) (2) * 08320-61000 SCREW (4)
H150
Nissan Performance racing parts used to sell an LSD for H150 -- as used by the 1975-1978 B210 & 1979-1982 B310, part number 38420-RS210. As of 2018, Nissan USA (parts.nissanusa.com) still shows it in the PDF catalog (page 53).
Occasionally Nismo LSD units are still for sale:
Google search
While this photo shows a 4.375 gearset bolted to it, the LSD unit can be used with any H150 gearset
Aftermarket H150 LSD by Car Wash
Occasionally offered for on Yahoo Auctions Japan like this diff head with LSD installed:
{{Photo|H150_LSD-2.jpg}
H150 LSD Parts
Pitroad sells parts to rebuild the H150 LSD.
38433-RS210 Friction Disc (6) 38432-RS210 Friction Plate (4) 38435-RS210 Friction Plate Spring (2) 38436-RS210 Friction Disc Spring NLA
H165
Nismo
LSD 2-way with 24 x 23T splines 38420-N5020 for Type I carriers * H165 old type: 3.889 to 4.625 旧型 * H165B low-tooth: 38420-N5020 3.700 to 4.875 並歯型 38420-RS110 for Type II carriers * H165B high-tooth: 3.154 to 4.875 高歯型
38420-A1260 L/S ASSY (TYPE II)
Also see H165#Nissan_Competition
AE86 Swap
See main article: AE86 LSD Swap
Pitroad/TRD
Pitroad sells a brand new LSD for the H165B axle (1985-up Sunny Truck) for about $1200 USD. It is from TRD (Toyota Racing Development) and is a bolt in when using the AE86 ring gear bolts. Pitroad H165 LSD or TRD
You can also buy the AE86 LSD (PN 41301-TA005) direct from TRD, be aware however that this is untested, and probably won't fit most H165 carriers. About $850 USD
Special stepped bolts can be used with the M10 type H165.
H190
H190 axle assembly from a 320 is narrower than a 1200 axle, so is a good candidate for a swap.
Nismo M-99996-T3011 $600 Detroit Locker
Nismo H190 Limited-Slip Differential units
For North America, optional H-190 LSD for the Hardbody when equipped with the Z24 or KA24E (2WD only, Four-cylinder only).
1988-1994 (D21) & 5-1996.5 (D21U) 38420-G7020 DIFFERENTIAL ASSY LSD (OPTION) 38303-10V02 LABEL-DIFFERENTIAL "LSD" LABEL-DIFFERENTIAL "USE ONLY LSD OIL"
CA200
Nissan CA200 axle, salisbury type, is an R200 gearset in live axle form.
AC brand for 29 Spline C200 Axle $580 USD
Will R200 LSD and VLSD fit into CA200?
Phantom Grip
Phantom Grip is an inexpensive LSD, which is spring-loaded LSD instead of the conventional clutch-pack LSD.
See main article: Phantom Grip
Depending on how you drive a phantom can last for a long time, to my memory mic had it in a rally car for 2 years then I had it in a road car for bout the same and at the end it started slipping but just needed to be re shimmed.
POST supafatto
Torsen Diff
Torsen differential works on a gearing principal and has no friction plates:
- Superior limited slip action, unless one wheel loses 100% traction
- Superb for street suspension or soft racing suspension, where there is little chance of a wheel coming off the ground
- If a wheel comes off the ground it stops working
For more information, see POST LSD vs Quaife ATB
1.5-way vs 2-way
Nismo sold both 1.5 way and 2 way LSDs. For street use, a 1.5 way is the best way to go.
The 1.5 way is a common LSD for racing as it does not give understeer on de-acceleration through cornering but gives a hard clamping force under hard acceleration, when normally you would break traction.
2-way generally causes understeer and is somewhat like a locked spool. It struggles to turn around in the street, quite similar to a welded diff, with tyres chirping and wheel spin required to get it to turn around.
Factory
Japan
LABEL-DIFFERENTIAL 38308-10V02 LSD/ノンスリシプ デフ シヨウ/リミテッド スリップ デフ シヨウ * C22/GC22/TC22/C23,D21/WD21/D22,K30,K30S * VE24/WE24,AC34,JR50,R33,R50,R20,Y60
38420-N9000 4-pinion * 720 8004-8303 4-pinion * S110 8204- HE41.FJ20
38420-41W00 2-pinion * 720 8004-8303 2-pinion * 720 8303-
North America
D21 C200.Z24I.OP D21 H233B.(VG30I+VG30E).OP D21U R50 S13 R200 VLSD 4WS 1990- S14 R200 VLSD OP. WD21 WD22 Z31 R200 VLSD, LSD
Labels: * 'LSD' * 'USE ONLY LSD OIL' * 'VISCOUS LSD'
38303-10V00 LABEL-DIFFERENTIAL 'VISCOUS LSD' * S13 1991- R200.4WS
38303-10V01 LABEL-DIFFERENTIAL 'LSD' * D21 * WD21 0889-0292 VG30E.OP
38303-10V02 LABEL-DIFFERENTIAL 'USE ONLY LSD OIL' * D21 * D21U * R50 * WD21 H233B+C200 * WD22 VG33E.SE+VG33ER+VG33E.OP
D21U 38420N DIFFERENTIAL ASSY-MECHANICAL LSD 38420-G7020 38420-S9200 38420-T6070 <> 38420-T6073 [C200] Z31 [R200] 38421S CASE SET-DIFFERENTIAL 38410-40F70 0188 VG30T.SS.MT.F5 $558 USD * VISCOUS LSD 4-pinion RC37 38421-71S26 0487-0887 VG30T $915 USD 0887- VG30T.(GL+GLL) * LSD 4-pinion RC37
Locking Diffs
A "locking" differential is another animal. When locked there is no slip -- not just limited slip, but none at all. When unlocked, it's the same as an open differential. These are used for racing or for seriously slow off-road work.
Locked diffs are also useful for circuit racing. Many race cars from all sorts of categories use locked diffs. The understeer that is apparent on street/drag cars with locked diffs can easily be eliminated with proper (race) suspension geometry. These settings (camber, castor, and toe) will not be practical for street use though.
L18_B110
There are different types of locking diffs.
Air Locker
The ARB air-locker is popular with Jeeps and other off-roaders. When the dash-mounted switch is flipped, air pressure locks the diff gears together
Detroit Locker
The "Detroit Locker" was used by some high-performance Ford vehicles in the 60s and 70s. The Locker may be the only modern road-going locking differential, as it can automatically lock and unlock. It is sort of a hybrid between an LSD and a Locker.
Spools
For drag racing, the spider gears can be replaced with a sold unit so that both axles are always locked together. This is called a "spool". It is similar to a welded diff, but is a bolt-in part made for this purpose.
Welded Diff
The "poor man's" locking diff is to have the spider gears welded together so that it works like a spool, but is obviously cheaper. The danger is of a bad weld and having it explode on the race track.
Using a spool or welded diff gears on the street is illegal in most countries, and can be dangerous, especially in the wet. The danger is of spinning out as the wheels do not turn independently, but the inside wheel is forced along the same as the outer.