Merv, I didn't drive it with the R33 centre, sorry. In my S15 it hooked up nicely but wasn't dealing with big V8 torque. Apparently in the Nissan S15 service manual it says, "use API GL-5 : Never use LSD exclusive gear
oil. Use standard differential
oil." I've read similar comments in many places. I believe the viscous LSD
oil contains modifiers to deal with the clutch packs and this is not needed in the mechanical LSD.
Edit: I let a bit of the oil out of mine and it looked and smelled OK so I haven't changed it.