Lifespan of VLSD

[WhiteS13]

I know that clutch ones need rebuilding after a few years of beating.  How about the VLSD's?

What would be an indication of it going?  My car seems to twitch a bit to the right before launching hard.

[drift freaq]

well I would make sure the gasket is not leaking . I have never heard of one going bad of course that also depends on how much abuse you give it.
No idea really.

[yenpit]

any limited slip diff should last just as long as an open diff, unless it is REALLY abused like drift said.

[Krunko]

what's the difference between VLSD and LSD?

[SaintlyCharBoy]

we.. all VLSDs are LSDs... but not all LSDs are VLSDs, you know?
did that make any sence to any one but me?
VLSD is simply more specific
i know that there are geared types, but i am still a bit unclear as to how exactly a VLSD works, i am under the impression, but am by no means sure that it works by allowing pressure plates to slide on one another...

please enlighten me oh nissan gurus
Sean

yeah, the v stands for viscous.. and basicaly when one tire starts spinning, it heats up this liquid and makes the 2 plates come together..... so,, soon after one tire spins, both will start,, hopefully grabbing..

[240 2NR]

The "V" in VLSD stands for viscous.

It will basically operate like an open diff durning normal conditions when both plates spin at the same speed (no wheel spin), however when one spins at a rate faster than the other, the viscous fluid between them heats up and becomes more viscous.  At some point depending on the fluid it will "lock" the two together and force both wheels to rotate instead of just one.  Then when they are both rotating at the same speed again, the liquid will cool and operate independently.
As for exactly how independt they operate I'm not sure, since rotating an open diff by hand even off the car is said to be nearly impossible, whereas the open diff can be spun by a child.  There however must be some independence or it would just be welded together.
This is my basic understanding of the principles.

As for life, I would say treat it like an open diff, and change its fluids.  There are two kinds in the VLSD, the same gear oil you use on the open type, and the viscous fluid in the lsd unit.  

[240 2NR]

VLSD - Viscous limited slip differential, found on cars like the 240, subarus, and the RX-7 (3rd gen at least)

Torsen LSD - all geared type, quaife, audi

Helical (spelling?) LSD - clutch type, KAAZ, Lancer evo

[transient]

How does the torsion type work? I've been thinking about getting a clutched LSD (kazz specifically)

[Jeff240sx]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from 240 2NR on 12:27 pm on Feb. 22, 2002
There are two kinds in the VLSD, the same gear oil you use on the open type, and the viscous fluid in the lsd unit.
</td></tr></table><span id='postcolor'>

I think you were right up to there. &nbsp;The &quot;liquid&quot; is actually silicone parts. &nbsp;The silicone is easily expanded by slight changes in temperature. &nbsp;And as far as I know, in a VLSD, like our cars, there is only one fluid that goes in it. &nbsp;Cuz there is a bright, caution orange label that says &quot;Use only SILICON GEAR OIL.&quot;
No. &nbsp;My car doesn't say that, it's open, but a friends says exactly that, on a Supra.
-Jeff

[240 2NR]

I could certainly be wrong, I assumed the silcone was in more of a fluid form, and that there was still a normal gear oil in the pumpkin and a viscous fluid in the unit. &nbsp;I'll check the fsm tonight if i remember. &nbsp; &nbsp;

[whateverjames]

when i worked for an oil change shop, we had to add some kind of silicon stuff after we added normal gear oil, to certain trucks and suv's. i think i know what you're talking about.

[junia]

I remember reading in an option 2 magazine a few years ago about adding metal shims(only word that comes in mind) between the couplings to make them grap a little harder. &nbsp;In the magazine they cut the shims out of sheets of aluminum and expiermented with different amount of shims that was used and how much the diff would grab when they were driving. &nbsp;Just though I'd throw that out there for those that wants someone who want something better than a regular vlsd but can't afford it.

[MeanRex7]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (240 2NR @ Feb. 21 2002,11:33)</td></tr><tr><td id="QUOTE">VLSD - Viscous limited slip differential, found on cars like the 240, subarus, and the RX-7 (3rd gen at least)

Torsen LSD - all geared type, quaife, audi

Helical (spelling?) LSD - clutch type, KAAZ, Lancer evo</td></tr></table><span id='postcolor'>
Wrong sir.
3rd Gen RX-7's have TorSen LSD's (Torque Sensing)

Series 4 Second gen RX-7's (1986-1988) have clutch type LSD's

Series 5 Second gen RX-7's (1989-1992 no 92 in US) have Viscous LSD's

Here is a great right up on differentials and the different types, I would at least take a look at the main types of LSD's (clutch, torsen, viscous). Although lockers are fun (NO YOU DO NOT WANT ONE IN A SPORTS CAR) <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>
http://www.howstuffworks.com/differential.htm