Millers have a selection of Differential Oils GL5:

GL5 (SAE 90, 85W140):  GL5 specification is for highly loaded hypoid differentials as fitted to most cars from 1960 onwards.  Also suitable for transmissions with brass & bronze components.

LS 90 GL5:  Limited slip, hypoid gear oil consisting of high quality solvent refined base stocks with E.P. additives and friction modifiers, for use in vehicle axles which incorporate limited slip.