After purchasing an lsd and rebuilding it with new bearings one needs to fill it with fluid. Im sure the fluid is available from ford, however I gather one can inscrease the amount of locking the diff gives by altering the fluid density/viscosity?

Has anyone had this done? If so what is a good fluid to refill the diff with?

Cheers

You've taken apart the LSD part of the diff which mounts to the left hand side of the differential gears? I didn't think this was a serviceable part. I inspected and cleaned my sierra LSD when building the car, filling it with Castrol diff oil when I'd finished but I didn't open the LSD thingy.

I havent personally, but Ive heard on passionford it can be done!

I guess from what youre saying the diff casing is full of conventional oil and the viscous coupling is full of this silcon fluid?

Yup, that's it. With the diff in position, fill until it is level with the bottom of the filling hole and you're done.

EP 80/90 for the bevel gears. The trick clutch bit is sealed and encased.

I just heard that by changing the silicon fluid one could alter the locking characteristics of the diff. It was a gearbox specialist who mentioned it tho so I guess no user serviceable parts doesnt apply to them :p