limited slip rear diagnosis

[MakotoS13]

today after work i decided to find out if i have limited slip and expected the worst. well, i get in gravel with a friend behind the car and drop the clutch. 2 marks exactly the same side by side.

okay, could be just the gravel, lets try it on pavement. we get it on a solid surface and i drop the clutch again. squeel, stop, 2 marks side by side, identical, and he saw both tires spin at the same time again.

i'm like, "rad, that's pretty cool". so i get home to share my joy to be told:

*****: Open does that most of the time
*****: big confusion
*****: open goes to eather left right or both

uhm, that pretty much contradicts all i know about limited slip differentials then i talk to another guy from the forums who calls b/s. idunno, perhaps there's some unique nissan thing that causes this so i'm posting here to find out for sure cause this defies all i know about differentials.

is there ANY way an open diff would spin both tires every time they lost traction?

[mike13]

no... my open diff sucks so bad that my right rear tire spins when pulling out of my parking space, or into traffic. so damn annoying.

[noahrexion]

if its not an SE with HICAS then you dont have a stock VLSD...
Yes an open diff can drop two black lines if teh tires friction/grip isn't that great....

[drift into a curb]

Just jack up the rear by the differential and spin one wheel. Both wheels should spin in the same direction. If the other wheel spins the opposite direction, it's an open diff.

[ZenkiS14]

look mike13, if you have a manual, then go pop the clutch a few times on pavement, and tell me what you see... both wheels WILL spin.

And for those of us unfortunate to have automatics, do a "braking" burn out or what ever (lightly push brake and floor the gas at the same time you will spin the back wheels) and you will leave 2 marks also.

As mike13 said TURNING will cause the one tire fire action-BECAUSE there is less weight on one side of the car. The best way that I use to see if there is an LSD is to not be lazy and just jack up the whole back of the car, put it in neutral and just turn one of the wheels, if the other spins the opposite direction, the you have an open diff.

THE BASTARD WAY- Go to an empty parking lot turn the wheel all the way to one side then slowly start to rolling and gradually work it up to where you are have fully depressed the gas. (DON'T POP CLUTCH) If the car just whips around, chances are you have LSD. If you don't you'll probably just leave this black mark in almost a perfect circle about 7ft in diameter. This is because the inside wheel of the car has less weight do to the properties of centrifigal force.

[doh boy]

put one tire in dirt/puddle/gravel/something that provides little traction, then the other tire in pavement, and then rev up drop the clutch, if the tire leaves a mark on the pavement you have LSD, if not then no.

[DuffMan]

The best way is to jack up one rear corner till that wheel is off the ground but the other is not. Leave the car out of gear and leave the ebrake off. If you can spin the wheel its open, if not its lsd.

[cdlong]

if one wheel is fixed and the car is in gear the other wheel won't spin, open diff or not.

you could also look for the sticker that says VLSD.

[sykikchimp]

some these are silly, and wrong.

Check for diff:
Jack rear of car completely off the ground.
Put car IN GEAR. (car off)
Turn one wheel with your hand.

Open diff will spin the other tire opposite direction. VLSD, and clutch will spin same direction.

Without the car IN GEAR during the test, you could get the other wheel to spin the same direction, since the drive shaft will spin.

And whoever told you "open does that most the time" must not have a clue. My car with open would ONLY spin both tires on extremely wet roads, and ice.

And for god sake, DON'T put the car in gear/drive with the engine running with one tire up on a jack.. This is just ASKING for trouble.

[mellojoe]

my open diff leaves two black mark if I drop the clutch. Many times, though, one will peter out before the other (after like 4 or 5 feet the two marks fade and one usually is a little longer than the other).

But, for a short BLIP of a burnout, then the two are very similar and are almost identical... And I can do that just about every time.

BUT: on a donut, or a power-over turn, I can get one wheel to spin leaving a single black arc. And I know I have an open diff.

PLEASE: jack the rear of the car completely in the air (BLOCKS IN FRONT OF THE FRONT TIRES!), and spin one wheel. If (while the car is in gear) one wheel spins forward and the other turns backward, then you have an open diff (exactly like I did). If both wheels spin forward, then you have an LSD.

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Thats the best way to be sure.

[S14DriftR]

open diffs can do that, the one on my s13 acted like that alot but had really shitty tires, my s14 that had nice grippy tires and an open diff would only spin 2 in wet or on gravel, so maybe the amount of grip you have has alot to do with it.

[sykikchimp]

the amount of grip you have has everything to do with it.

[MakotoS13]

just wanted to check with some other people before calling the guy a retard and looking like a jackass.

*puts LSD on list of first round mods*