i sometimes experience a whine when accelerating quickly and the down changes are a bit rough, what do you think it is?
when i got my diff oil replaced the bloke showed me a few things underneath, said my universal shaft (i think) was worn out, could that be it?
with the lsd, on the oil filler bolt on the diff there should be a tag indicating if its lsd, mine has it but he said the bearing was buggered so it wasnt doing what it should.
As for the whine your hearing fair chance that it's the diff pinion bearing (very common with IRS diffs) although that has nothing to do with the limited slip of the wheels, if it's an LSD you should be able to spin 2 wheels under heavy throttle around corners and such but at this age and a few k's your LSD cones (2 tapered circular cones inside the diff center, that contact another surface) are probly worn out, if both these factors are your problem and it concerned you then a diff overhaul is more than likely needed, or find your self a good second hand one.
As for the clunking downshift of the gears that's also a common problem, it's the 'check balls' hitting the valve body separator plate (little ball bearings in oil galleries that cover holes on a steel plate inside the auto to control oil pressures ect) they eventual start to wear away the separator plate, depends on how bad it is if you can barely feel it or it's clunky very harsh, you can bye new separator plates, not sure wear but I wouldn't worry to much if it's not to bad, cheers
