Saalro

iTrader: (8)

I've got a Classic MY00, do these use standard diff or LSD?

Thanks

172sport

iTrader: (6)

Viscous I believe.

jonny_693

iTrader: (5)

Which one there is three? I think it goes, Mechanical front, mechanical centre with a viscous coupling. And a LSD rear.

Splitpin

All differentials are mechanical so not quite sure how you're using that term there.

On a UK car the front diff is open, and the centre and rear are viscous coupled. All three are conventional bevel gear designs.

joz8968

iTrader: (13)

SP, I thought the centre and rear VCs were a simple input shaft and output shaft with intermeshing concentric circular plates attached to each shaft(?). The plates are submerged in a special... viscous... silicone fluid, all encased in the diff housing.

As the shafts rotate at the same speed and the plates turn through the silicone, then the torque is sent to either end/side at a ratio of 1:1, as they're in equilbreum.

As soon as there's any speed differential between the shafts (i.e. one end's or side's wheels slipping), then the plates attached to the shaft turning faster shear through the fluid, raising its temp, thus changing its state to anything from between 'fully fluid', and 'fully solid' and partially locking, or fully locking, with the slower spinning shaft. This allows the torque to be sent to the, initial, slower spinning shaft's end - what percent, is dependent on the speed differential. It's this fluid's ability to be in a state between fluid and solid that allows the cente VC to, effectively, deliver anything between 50-100% of the torque to the front or rear (or 25%-100% to either rear wheel in the case of the rear VC).

I apologise if this is not the case, but that's how I understood the internal workings of the VC.

Splitpin

That's what the viscous couplings look like, yes. However, if you're saying that you think that's all that a viscous diff consists of, that'd be incorrect.

In each of those units there is a conventional bevel gear diff [B]andand a viscous coupling. The diff does what every differential does and then the VC provides the limited slip qualities.

Your general understanding of the coupling method is pretty good, but, if I'm reading your post the way you intended, that's only half of the story in a viscous LSD. It's a diff *and* a VC, just like a plate diff is a diff *and* a friction pack.

joz8968

iTrader: (13)

Yes of course! Because if there was no 'conventional' bevel gear IN ADDITON, then when at equilibreum with the fluid only, there'd be no way of connecting one shaft to the other! lol What an oversight.

Yeah, I was basing it on the compact centre diff as fitted to Integrales.

scowen

so what would be the effect of having a set of smaller profile tires on the rear to the front or vise versa would this cause confusion to the way the diff works & if so could id cause any damage ?

joz8968

iTrader: (13)

They'd have to be like tractor- or skateboard-sized rolling circumfereces at one end for that to become in issue! (an exaggeration, but you get the idea). TBH, I don't know what difference in RC front to rear would there have to be for tranny wind-up to occur? 1", 2", 5", 1'...?!!!

Why would you want to ask that question anyway? The system's been designed to be 'correct' from the outest, when the same size tyres are fitted front and rear!

Or are you after that 70's Carlos Fandango big-tyred, jacked up rear.... small front-wheeled, nose-down, look?!...

jonny_693

iTrader: (5)

Yes it was a bad use of the term in hindsight what I meant was not 'electronic' but 'open'.

Saalro

iTrader: (8)

I'm going to have to read up on all these terms lol.

Thanks everyone