Supercar center diff question

[wraith]

Phil,

I noticed the output shaft turns easily by hand while the housing stays put. Is this because theres no oil in it, or is that the nature of the design. I only turned it a couple times not to cause any damage in case its not a good idea. Does this mean the rear wheels can be towed on the ground on occasion unlike the stock setup or is it just as damaging as when it happens to the stock unit? Any special kind of fluid needed?

Thanks
Sam

[Supercar]

Hi Sam,

It's a helical gear-type differential. The gears spin pretty much freely when there is no load. There is no VCU inside, this is why you can turn it easily by hand.

Once the engine torque is applied to the diff body, it will split it with 40% going to the front and 60% to the rear. It will also generate friction inside. A plenty of friction, which is equal to 20% of the transmitted torque. So it can send that generated friction to the front, making it a 60/40 split, which is good for slippery conditions, or 20/80, which is good for high traction asphalt.

Towing the car with one axle dragging is still not recommended. Same goes about installing tires of a different diameter front to rear. Those high-friction helical gears are not meant to be spun at high relative speeds for prolonged periods of time. But you can do some parking brake turns with this diff, if you also push the clutch in, which is something that you could not do with the VCU.

No special transmission fluid is required.

Philip