LSD (differential!)questions.

Count Knobula

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Jan 31, 2007
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From wikipedia (sorry) I read that mark 1 and 2s (some of them) had limited slip differentials from the factory.

Do any mark 3 models have them?

Any easy way of knowing which cars have them?

I'm assuming mine doesn't (89 turbo AT) but am interested in the possibility of having one, how much am I looking at paying?
 

JtWo

Sniper
Apr 10, 2005
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your car should have one. you might be one of the freak turbos that dont have a diff though. BTW I'm thinking about selling my spare 3.73 diff ;]
 

Count Knobula

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Jan 31, 2007
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OK.

1 - How can I tell if I have one?

2 - How much would yours be? (PM me if you like)

3 - What's the stock final drive ratio?
 

Mischief7m

Broke and Lovin It
Sep 13, 2007
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IIRC

Pre 89 turbos had 3.91's (LSD)

89+ had 3.73's (LSD)

NA's had open 4.11's (NOT LSD)

and Sport package NA's Had 4.11's (LSD)

I believe JZA70's had 4.11 LSD's as well, but don't hold me to that one
 

Count Knobula

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Jan 31, 2007
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So I have an 89 turbo and it should have a 3.73 LSD?

That's great info, thanks.

As you can tell I know nothing about LSD. My good friend who is also my mechanic wanted to know the final drive ratio (I hope I word it right). Is that 3.73? Dont sound like a ratio to me lol

Does the fact my car is auto change anything? Or have I definitely got an LSD?
 

bmoss85

Permanently Banned Scammer
Apr 14, 2007
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Count Knobula;1141924 said:
From wikipedia (sorry) I read that mark 1 and 2s (some of them) had limited slip differentials from the factory.

Do any mark 3 models have them?

Any easy way of knowing which cars have them?

I'm assuming mine doesn't (89 turbo AT) but am interested in the possibility of having one, how much am I looking at paying?

you should have one unless someone swapped it at some point. when you do a burnout does it leave 1 or 2 marks, thats an easy way to find out.

some good info here>http://www.supramania.com/forums/showthread.php?t=47729&highlight=decoding+vin
 

Count Knobula

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Jan 31, 2007
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I DON'T burnout, I'm in an automatic that is bad. (swapping out for R154 on Friday which will be nice).

Are there any numbers/labels or whatever I can look at to make sure I do have an LSD?

thanks and sorry for how dumb/elementary I sound.
 

Count Knobula

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Jan 31, 2007
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Looked at that thread.

G305 = 3.73:1 4-pinion 8.0" 89+ Turbo Diff (with-LSD)

Is what I should have. Where would I find this code/name? in the doorframe?

sorry for wasting everyones time. looked at the vin - G305, your thread was correct.

Where can I get the final drive ratio for this? Am I right in thinking that it's adjustable? (by more skilled hands than mine of course)
 
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Keros

Canadian Bacon
Mar 16, 2007
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You're more likely to have an LSD than to not have one.

Next time the back end is in the air, give a wheel a spin: if they turn the same way, LSD, if they spin different ways, open diff. This is not true for all kinds of LSD's, perhaps someone else knows more specifics.
 

Count Knobula

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Jan 31, 2007
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Keros;1141977 said:
You're more likely to have an LSD than to not have one.

Next time the back end is in the air, give a wheel a spin: if they turn the same way, LSD, if they spin different ways, open diff. This is not true for all kinds of LSD's, perhaps someone else knows more specifics.

well my VIN says I do. The car will be in the air on Friday so I'll check then too.
 

GotTurbos?

2J = Here; Swap = Near
Apr 24, 2006
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Dallas, TX
mischief7m;1141942 said:
IIRC

Pre 89 turbos had 3.91's (LSD)

89+ had 3.73's (LSD)

NA's had open 4.11's (NOT LSD)

and Sport package NA's Had 4.11's (LSD)

I believe JZA70's had 4.11 LSD's as well, but don't hold me to that one

The NA's had 4.3x's not 4.11, the 4.1 is the torsen differential.

Easy way to find out if you have an LSD is by jacking up the car by the rear dif. You can look at the dif and it should have an LSD sticker on it. However the sure way to check is to spin one of the rear tires while it is off of the ground, if they both go the same way then you have an LSD, if they go the opposite way then you dont.
 

Count Knobula

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Jan 31, 2007
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GotTurbos?;1141998 said:
The NA's had 4.3x's not 4.11, the 4.1 is the torsen differential.

Easy way to find out if you have an LSD is by jacking up the car by the rear dif. You can look at the dif and it should have an LSD sticker on it. However the sure way to check is to spin one of the rear tires while it is off of the ground, if they both go the same way then you have an LSD, if they go the opposite way then you dont.

OK, but why bother? My VIN says it had one and I can't see why any of the previous owners would have removed it and put in a non-LSD instead?!
 

SupaMan

Want The Boooooossttttttt
Oct 12, 2006
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the tag for the diff is on your firewall drivers side.

34nmae9.jpg


the line of numbers your looking for are the four next to the 5 that circled.
 

Count Knobula

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Jan 31, 2007
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Atlanta
SupaMan;1142029 said:
the tag for the diff is on your firewall drivers side.

34nmae9.jpg


the line of numbers your looking for are the four next to the 5 that circled.

alas, the pic is blocked for me (at work)

is it also on the VIN? because I found G305 on my VIN sticker, which according to the thread posted earlier that is what I'm looking for.
 

Keros

Canadian Bacon
Mar 16, 2007
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Calgary
If you ever drove it in the winter, you'd know if you had an LSD or not, lol.

It is not a bad idea to actually know for certain, rather than the stickers and number plates, if it has an LSD... as that it's a ~20 year old car, someone could have easily detonated the diff and replaced it with an open diff.
 

suprarx7nut

YotaMD.com author
Nov 10, 2006
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www.supramania.com
Keros;1142176 said:
If you ever drove it in the winter, you'd know if you had an LSD or not, lol.

It is not a bad idea to actually know for certain, rather than the stickers and number plates, if it has an LSD... as that it's a ~20 year old car, someone could have easily detonated the diff and replaced it with an open diff.

Or someone like me could have owned both a turbo and N/A and put the lsd into said N/A and put the open diff into the turbo.

But I'm not a douche, so I'll be swapping them back when I sell the turbo. :)
 

Poodles

I play with fire
Jul 22, 2006
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Fort Worth, TX
You'd still be swapping the pumpkin which has the sticker on it... (unless you're REALLY a douche and swap a few more things around...)

End comment, more than likely the OP has an LSD...
 

ZoomZoomZoom

On the road again..
Dec 9, 2007
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KY
Count Knobula;1141950 said:
So I have an 89 turbo and it should have a 3.73 LSD?

That's great info, thanks.

As you can tell I know nothing about LSD. My good friend who is also my mechanic wanted to know the final drive ratio (I hope I word it right). Is that 3.73? Dont sound like a ratio to me lol

Does the fact my car is auto change anything? Or have I definitely got an LSD?

I asked my mechanic which rear diff my auto had, and he did a simple test. While the car was in the air, he spun the rear tire slowly one time. He told me to count how many times the rear axle (right term here?) rotated. Just so happened to be 3 and 3/4 turns. Thus, your 3.73 ratio explained.

There were no stickers to be found on my car. Probably because it was covered in transmission fluid :3d_frown: