Can the viscous coupling fluid be changed???
 

Mine is showing the typical signs that when its hot the wheels bind up in tighter turns.

Whats the best solution? Go to the dealer and get them to change it, go for 2nd hand unit and risk it being a duffer, get a specialist to change the fluid, or go for one of the adjustable diff conversions.

BTW my car is a classic turbo 2000, model year 2000.

Cheers for your advice guys!

JP.

Its best left to the professionals. The below is copied from a Ford XR4x4 site.

Viscous Diffs
The viscous differential also has interleaved plates, and in fact works because of the viscosity (internal friction) of the silicone fluid that fills the gaps between the plates. The plates therefore do not actually touch one another. The percentage of torque transfer varies with the difference in speed between the two wheels, partly as a result of the plate design and spacing, and partly because of a physical property of silicone fluid that it experiences virtually no change in viscosity when heated. If one wheel is rotating only a little faster than the other, only a little torque transfer occurs, when there is a big difference between the speeds of the two wheels, the viscous differential will transfer up to 95 percent of the torque to the wheel with traction. Because of the difficulties in handling the silicone fluid, servicing a viscous differential can be accomplished only with special equipment. The silicone fluid is under pressure, and there is an air bubble of known (and controlled) volume included in the differential casing. Any deviation from the correct amount of pressure or air bubble volume can radically change the characteristics of the differential.

Not sure of the relevance to Scoobies but I imagine there much of a muchness.

I have no connection to this place but have heard good things about them.

http://www.bellengineering.co.uk/2.html