Does Castrol synthetic 7590 gear oil have a limited slip additive in it?

I just had both my front and rear differentials serviced. They used Castrol Synthetic 75-90 but I don't see anything on my bill about a limited slip additive.

Does the Castrol gear oil already have one in it?

I have a track lock in the rear, and an ARB air locker in the front. If the gear oil doesn't have the limited slip additive, I'll of course put a tube in the rear, but would the front ARB need it?

Thanks

none for the arb.

change them yourself so ya know the condition of fluid/gears adn all that

Hmmm, when I put my auburn in the instructions said specifically NOT to use synthetic gear oil. If it's anything like the wet clutch in my 81 Yamaha it will allow the clutches to slip too much, in the bikes case it would not go anywhere in gear..