I bought a vlsd from jspec.com and was wondering how i can find out what the gear ratio is,  i dont want to try and count the teeth.  Some of the numbers on the differential are

A5-9500330b and right under that is 19768. Its looks as though those were printed on there some how.

these are casted into the housing:
68311
40F00

This looks as if it was stamped on there:
331B
A5

any help would be much appreciated.

philip

Is it an aftermarket vlsd or is it a OEM part?  The OEM part is ~4.09 ratio.  Fairly high if you analyze it.  If its aftermarket I would try to contact the company about it.

I belive it is an oem part, but it is from japan so i think it may have come off of a turbo s13, which i belive have lower gear ratios.

Well I really cant answer your question properly if you already know it.  I know the transmission gear ratios didn't change, so why would they change the rear end ratios, I don't know.

It's either 4.083:1 (KA24DE, SR20DE, SR20DET manual) or 3.916:1 (SR20DET automatic), most likely.  There's a smaller chance it's a 4.363:1 unit from a CA18DET.

If you don't mind opening up the diff, you don't have to count the teeth...  IIRC there should be a set of numbers stamped on the ring gear itself.

49/12 = 4.083:1
47/12 = 3.916:1
48/11 = 4.363:1

thank you for the information, that was exactly what i was looking for, it is 4.083 gear ratio.

so the higher gear ratio is the more desireable one?

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (exitsanity @ Sep. 18 2002,5:50)</td></tr><tr><td id="QUOTE">so the higher gear ratio is the more desireable one?</td></tr></table><span id='postcolor'>
The higher the number, the shorter the gear, the sooner you will have to shift... I know someone with the 4.36 and he has virtually NO use for 1st gear before he redlines and has to shift. This being said, you will get worse gas mileage the shorter that gear is.

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (guidot @ Sep. 04 2002,02:34)</td></tr><tr><td id="QUOTE">Well I really cant answer your question properly if you already know it. I know the transmission gear ratios didn't change, so why would they change the rear end ratios, I don't know.</td></tr></table><span id='postcolor'>
Guidot,
SR20DET motors in Japan will have a lower final drive ratio, as was explained in the 2 posts above mine, because you can stay in that gear longer.
Normally, that's not good, but when you are boosting, you would like to stay in the spool-up area for as long as humanly possible. &nbsp;That's why. &nbsp;Same with 300zx NA vs. TT. &nbsp;The NA has our gear ratio, while the TT has 3.8something.
-Jeff

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">It's either 4.083:1 (KA24DE, SR20DE, SR20DET manual) or 3.916:1 (SR20DET automatic), most likely. There's a smaller chance it's a 4.363:1 unit from a CA18DET.
If you don't mind opening up the diff, you don't have to count the teeth... IIRC there should be a set of numbers stamped on the ring gear itself.
49/12 = 4.083:1
47/12 = 3.916:1
48/11 = 4.363:1
</td></tr></table><span id='postcolor'>

ok this correct to a point.
The SR powered Turbo cars i.e. S14 and S15 came with 3.70:1 gears . I also am pretty sure it was the same with the S13 SR20DET cars . The 300zx TT &nbsp;also came with 3.70:1 gears .
as far as the CA18det ratio's are concerned you are correct

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (drift freaq @ Oct. 02 2002,10:38)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">It's either 4.083:1 (KA24DE, SR20DE, SR20DET manual) or 3.916:1 (SR20DET automatic), most likely. There's a smaller chance it's a 4.363:1 unit from a CA18DET.
If you don't mind opening up the diff, you don't have to count the teeth... IIRC there should be a set of numbers stamped on the ring gear itself.
49/12 = 4.083:1
47/12 = 3.916:1
48/11 = 4.363:1
</td></tr></table><span id='postcolor'>

ok this correct to a point.
The SR powered Turbo cars i.e. S14 and S15 came with 3.70:1 gears . I also am pretty sure it was the same with the S13 SR20DET cars . The 300zx TT also came with 3.70:1 gears .
as far as the CA18det ratio's are concerned you are correct</td></tr></table><span id='postcolor'>
according to Sam from jspec.com the s14 silvia LSD differential &nbsp;had the 3.92:1 gear ratio. He indicated to something on the casing of the diff itself referring to that.

hmm - would this also explain why I can't put her into 1st gear unless I am going so slow I'm practically stopped?

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">according to Sam from jspec.com the s14 silvia LSD differential had the 3.92:1 gear ratio. He indicated to something on the casing of the diff itself referring to that.
</td></tr></table><span id='postcolor'>
well it may have come in some of the cars but the info I had came straight from a ziliva member who lives in UK because I wanted to know and asked and he answered right out of his FSM.