Does LSD's viscous fluid ever wears out?

[One_Beer]

I heard people say that in time the VLSD will lose its viscousity and eventually become a regular diff. Also, some say that it never wears out??? So can anybody tell me for sure, and not just a guess.

Thanks

[240_Keyy]

it does, especially if you make buttloads of power and abuse it...

[corn322]

is there a way to change the fluid, or do you have to get a whole new whatever you call the little coupling thing

[trpower7]

Gotta get a whole new diff. In a VLSD the viscous pack is sealed and therefore can't be changed. You can change the regular gear oil which will extend the service life of the unit, but eventually the viscous fluid will wear out.

[One_Beer]

Thanks guys... So now how can you tell if your VLSD is going bad, or not working. Does lifting both tires on jack, and wheel spin thingy test will show if its bad or not working?

[trpower7]

Yep. Spin the same way, you're in good shape, spin opposite ways, you're SOL.

[240_Keyy]

Floor the gas, pop the clutch, count the stripes...

[One_Beer]

Both still spins in same direction. But how about under load???If the viscous fluid is losing its viscousity to expand, than would the grip on the plates become weaker under heavy load. Therefore, lose its grip. And the plates will start to slip...(open Diff.) So I must watch out for the used up VLSD eh...

I got 89 300zx VLSD, but I don't want to put junk if it is not working. Thinging about getting J30 VLSD $250 junk part with correct output shaft. And Change out the ring gear to 49/12 ratio. Is this possible?????

Thanks alot

[SingleCamSam]

It's a little more expensive than the junkyard route, but http://www.pdm-racing.com has oem VLSD units with less than 60k kilometers on them for $350. At least you know they work.

[One_Beer]

So can I replace the ring gear on J30 lsd with my ring gear on my s13 non lsd diff's???

[erich]

I don't think the fluid can wear out. The fluid's chemical properties make it thicker when hot, however the viscous coupler is a sealed unit that can eventually crack and leak. Once the fluid leaks out you have an open diff :-( I'm pretty sure you can get a new viscous coupler from Nissan.

[Unnatural]

I don't think the fluid can wear out. The fluid's chemical properties make it thicker when hot, however the viscous coupler is a sealed unit that can eventually crack and leak. Once the fluid leaks out you have an open diff :-( I'm pretty sure you can get a new viscous coupler from Nissan.

The viscous fluid does breakdown over time and will "wear out". This will cause the VLSD to be much slower in reacting when needed. Eventually, it may not respond at all because the viscous fluid can not create the needed pressure to lock the axles.

[trpower7]

Exactly, and no, Nissan does not sell another viscous coupling.

[turboex]

save you time and money and call this number and ask for bob. he has a nissan junkyard. he sold me a 96 vlsd for 200 shipped, flawless condition. tell him damian sent ya 1-860-642-4362

[BadMojo]

The viscous fluid does breakdown over time and will "wear out".

Coincidentally, Sports Compact Car mag just had an article about one of their project cars with an OE VLSD that was way past its prime. They replaced it with a shiny new Quaife helical limited slip differential.

[Unnatural]

Yes they did. I'm able to get Quaife ATB diff's, specifically the Nissan R200 version or any other, if anyone is interested.:naughty It's an excellent product.

_________________BrendanUnnatural Racing[email protected]

[Gmans13]

word

[ale89se]

You can change the regular gear oil which will extend the service life of the unit, but eventually the viscous fluid will wear out.

so how do you change the regular gear oil? i did it before i put it on the car. swapped out for an open diff.

[corn322]

so how do you change the regular gear oil? i did it before i put it on the car. swapped out for an open diff.

So... you need to know how to change regular gear oil, even though you've already done it?

[jr_ss]

Yes they did. I'm able to get Quaife ATB diff's, specifically the Nissan R200 version or any other, if anyone is interested. It's an excellent product.

_________________BrendanUnnatural Racing[email protected]

What can you get the diff's for? I looked on their site and it's about 1500 for a diff. I'm not saying that's bad especially since it has a limited lifetime warranty, but it's almost cheaper to buy a Nismo LSD, or a used S15 helical that won't wear out that fast.

Glenn

[ale89se]

after long hard uses ,ie. drift day like i just attended, you are supposed to change it.

So... you need to know how to change regular gear oil, even though you've already done it?

[Crunkrich]

Does anyone know on the average what mileage a VLSD wears out at?

[Red coupe]

I think thats really gonna depend considering some people probably never have it lock up (old women, ect) and some lock it up every day...I would guess in the mid 100k area?

yeah how much can you get the Quafe for?

[Crunkrich]

yeah i figured something like that, thanks for the info. i was aiming to get one from an automatic j30 which is likely to not have been driven by a sports enthusiast... but just watch now im gonna get crap for sayin that one lol

[Red coupe]

we have an utter lack of J30 owners, I think your safe on that one....We need more J30 owners, I know I wouldnt mind a J30T...Did they only come in auto?

[Crunkrich]

yeah thats not too good but then again good for me

i havent seen any 5 speed j30's but I wouldnt be surprised if there are