can someone explain to me how exactly a viscious lsd works. fluid...differential...help. my brother is thinking about getting one for his sileighty. and i wanna do a lil research on it. how does it compare to clutch, helical type. i dont like clutch type all that much (rebuilds and such)...but how does it compare to the other two?

 

A viscous type LSD functions exactly like a clutch type LSD with two major exceptions. Number one is the plates don't actually touch like they do in the clutch type unit. And number two is that they have a thick "viscous" fluid that, when churned by the plates, actually becomes thick enough to lock the plates together. The major downfall of the viscous LSD is that the fluid is temperature sensitive and will lose it's function at extreme temperatures. Prolonged use under extreme temperatures will cause breakdown of the fluid, and the differential will cease to function as an LSD, and function only as an open differential.

 

look at it like a small torque converter

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kendall &raquo;</TD></TR><TR><TD CLASS="quote">A viscous type LSD functions exactly like a clutch type LSD with two major exceptions. Number one is the plates don't actually touch like they do in the clutch type unit. And number two is that they have a thick "viscous" fluid that, when churned by the plates, actually becomes thick enough to lock the plates together. The major downfall of the viscous LSD is that the fluid is temperature sensitive and will lose it's function at extreme temperatures. Prolonged use under extreme temperatures will cause breakdown of the fluid, and the differential will cease to function as an LSD, and function only as an open differential.</TD></TR></TABLE>
so...to help retard some of the heating, would a tranny or some kind of oil cooler help? also, when the fluid completely breaks down, is it as simple as draining and replacing the fluid as i'm thinking. because it doesnt' sound like any kind of rebuild would be necessary since the "clutch discs" never really touch.

 

i don't think you wanna mess with the differential by tapping it lol, you would lose the pressure and i think it'll be too viscous to flow through the lines anyways.

 

but otherwise, when the fluid totally breaks down, is it as simply as draining and refilling?