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LSD in an S4 N/A?

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Old Jul 14, 2007 | 08:40 PM
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Cool LSD in an S4 N/A?

My 88 SE seems to have an LSD! Which doesnt make much sense. But whenever I do a burnout of drift it in a parking lot it seems to smoke both tires evenly. I know this wasnt an option for the SE and how would I check it to be sure that it is or isnt an LSD? Thanks!
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Old Jul 14, 2007 | 10:17 PM
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Jack up the back of the car and block one tire from moving, spin the other tire. If it spins freely then no LSD (or one that doesn't work anymore), if it takes some effort to spin it you've got LSD.
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Old Jul 14, 2007 | 10:53 PM
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do the burnout with the steering wheel turned fully one way and then check to see if you have two strips.

possibilities are that the previous owner could have installed LSD?
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Old Jul 14, 2007 | 11:36 PM
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When the wheel is turned all the way to one side and I pop the clutch it does leave two black marks that are even. It looked like an LSD to me, but just wanted to confirm. Now that I know, should I still use Redline Synthetic in the diff or should I use something else?
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Old Jul 14, 2007 | 11:56 PM
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it should say on the diff if its an lsd right where you fill the fluid... i heard redline is good stuff but im using neo synthetic and I have no complaints.
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Old Jul 14, 2007 | 11:59 PM
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with the skinny tires of a SE, you should be able to break both tires loose without any issues.

Of course an educated car owner would know that any car that has poor enough traction can have its drive wheels broken loose and that a burn out is hardly any sort of indication of a LSD.
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Old Jul 15, 2007 | 01:44 AM
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my 86 gxl has a lsd and its n/a
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Old Jul 15, 2007 | 03:12 AM
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Originally Posted by 86inthe530
my 86 gxl has a lsd and its n/a
All GXL's had a factory LSD. The SE (base model) did not, unless installed after the fact.
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Old Jul 15, 2007 | 03:17 AM
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S5 GXL's did not have an LSD.

If you have an LSD, there should be a tag on the diff that tells you its an LSD.
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Old Jul 16, 2007 | 10:26 AM
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From: NYC/T.O.
Originally Posted by Icemark
with the skinny tires of a SE, you should be able to break both tires loose without any issues.

Of course an educated car owner would know that any car that has poor enough traction can have its drive wheels broken loose and that a burn out is hardly any sort of indication of a LSD.
That's why you do it with the wheel turned one way.....I believe the inside tire lights up when you're cornering without an LSD and give it too much gas.....unless the open diff is broken.

Any good diff fluid is fine (Redline, Royal Purple, NEO, etc.)
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Old Jul 16, 2007 | 01:06 PM
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Originally Posted by Roen
That's why you do it with the wheel turned one way.....I believe the inside tire lights up when you're cornering without an LSD and give it too much gas.....unless the open diff is broken.)
Too tight of an corner and and if the inside has too little traction, it will break loose there as well with most all LSDs except Torsen based ones
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Old Jul 16, 2007 | 02:34 PM
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wouldn't the clutch-type and the viscous-type force the wheels to spin at an even or at least a non-smoking tire rate?
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Old Jul 16, 2007 | 03:35 PM
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Originally Posted by Roen
wouldn't the clutch-type and the viscous-type force the wheels to spin at an even or at least a non-smoking tire rate?
Yep, see that is the problem, the inside wheel needs to spin faster than the outside one.

So if you had say a locked rear, the outside one with the most traction would force the inside one with the least traction to spin at the same speed. With a clutch type or viscous that often results in the clutch pac slipping in the diff (a good thing) because it does maintain traction better.

Now with a Torsen, it sends the power to the wheel with the most traction as opposed to trying to make both wheels spin at the same speed.
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Old Jul 16, 2007 | 04:38 PM
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I do have custom wheels and tires. They are 17" tires and I believe the tires are a 215 series. I dont recall my diff has a stamp that has an LSD. Both tires seem to leave even strips of rubber. I will have to try the spin trick with blockin one of the rear wheels while on a lift.
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Old Jul 16, 2007 | 05:11 PM
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Originally Posted by RX7_Racer_84
I do have custom wheels and tires. They are 17" tires and I believe the tires are a 215 series. I dont recall my diff has a stamp that has an LSD. Both tires seem to leave even strips of rubber. I will have to try the spin trick with blockin one of the rear wheels while on a lift.
even easier... if you have a LSD, when both rear tires are up in the air, if you spin one side, the other side will spin the same direction.

Without an LSD the other tire will spin the opposite direction.

Now a viscous and torsen LSD will act different, but if it is a the standard S4 LSD then the above rule works
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Old Jul 16, 2007 | 05:19 PM
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a viscous diff will also follow the spin rule. Don't have experience with the torsen yet.
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Old Jul 16, 2007 | 05:55 PM
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Originally Posted by Roen
a viscous diff will also follow the spin rule. Don't have experience with the torsen yet.
Usually the viscous takes a pre-determined slip (usually a revolution or two)
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Old Jul 27, 2007 | 06:20 PM
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I lifted up my 7 and spun one of the wheels. The other one didnt turn either way. What does that mean??
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Old Jul 27, 2007 | 07:27 PM
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your open diff is broken.
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Old Jul 27, 2007 | 07:42 PM
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What does that mean? Broken how and why?
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Old Jul 29, 2007 | 02:07 AM
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instead of the open diff distributed the power evenly and having no limited slip characteristics, the broken open will mainly send power to one wheel, in any ciircumstance.
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Old Jul 29, 2007 | 07:25 PM
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Did you have it in gear? If it's in neutral, spinning one wheel may spin the differential input shaft instead.

-=Russ=-
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Old Aug 17, 2007 | 01:10 AM
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This might sound stupid, and I didnt search yet, but can you guys save me some time and tell me if my n/a s4 GTU (1988) has LSD stock?
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Old Aug 17, 2007 | 01:14 AM
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Originally Posted by Syonyk
Did you have it in gear? If it's in neutral, spinning one wheel may spin the differential input shaft instead.

-=Russ=-
bingo. put it in gear when you turn it. other wise youll spin it all day and nothing will happen.

my gxl's lsd actually fails the spin trick. sometimes the other tire will spin the other way. its pretty worn though, locks good turning left but unlocks turning right sometimes, but i still manage to drift alright with it like that.
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Old Aug 17, 2007 | 01:33 AM
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Originally Posted by 0verb00st
This might sound stupid, and I didnt search yet, but can you guys save me some time and tell me if my n/a s4 GTU (1988) has LSD stock?

yes it does, check the FAQ at the top of the page in the second gen specific section for more info
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