75w 90 any good one will do, redline, silkolene, TRD own oil.
But already told you :homer:
Of course TRD would recommend their own TRD 75w 90 as it has magical properties over the rest :teach:
It's pretty basic technology at the end of the day just needs some lubrication. Many oils will promise you the world filling your head with different advanced technologies. We use Toyota fluid and never have a problem. Knocking noises on LSD's is usually attributed to bad wearing in procedures, certain oils will help rid this but it's just masking a problem, the oil isn't why it does it in the first place unless you have a trick central differential system like you find on the Type R scoobies. They makes noises due to incorrect settings on the wrong surfaces but way more advanced than our basic inbox gearbox LSD's very different.
T