In theory, I think there should be a difference. If you were to try and characterise the 2 different types of diff by rotating one input at a variety of speeds and then measuring the torque to turn, they would be quite different. The balls diff would give a reasonably constant torque regardless of input speed. Not so with the gear diff due to the nature of the viscous friction... The torque would rise with input speed. This is the main reason for the difference in characteristics IMO.
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Originally Posted by Xracer
In theory there should be no difference, no pun intended!
A gear diff cannot slip under load whereas a ball diff can due to the very small contact patch between each ball and thrust plate, they are lubricated too!
The reason they 'feel' different when driving is because the ball diff IS slipping even when tightened down hard, the evidence to this is the maintenance required to replace the washers due to 'grooving' and pitting and the balls because they have become micro-faceted from slipping.
Using ceramic balls prolongs the ball life but the rings still suffer!
The initial tightening down also initiates pitting of the rings as they are relatively soft compared to steel and more so with ceramic balls.
It was interesting when discussing gear diff oil viscosity with a Schumacher member recently that they had reduced the recommended viscosity dramatically from their original build instructions to get closer to the ball diff handling 'feel' but of course a gear diff can never feel the same.
So it is down to preference when driving along with the acceptance that maintenance will always be the bane of the ball diff if this is the choice!
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