I run a toyota RAV4.2 uk model manual, 2ltr petrol.
here is the oil spec
for the g/box (actually it is a transaxle as there is no center diff) GL-5 SAE 80w90
rear diff (which is not an LSD) API GL-5 SAW90
A couple of years back, the dealer changed the oil but used their approved brand (castrol??)
I have used mobil synthetic gear oil previously in 2 & 4 wheel drive cars with good results. What bugs me is I cannot source synthetic API GL-5 SAW90 and most GL-5's are 75w90
any ideas or suggestions??
I know of no fully synthetics in SAE 90 viscosity grade gear oils, though States do have fully synthetics 80W90 (not sure if it's GL4 or GL5).
Sourcing for a fully synthetics in SAE 90 GL5 is akin to one sourcing for mineral oils in say, 0W40 0W30 engine oils.
In my tropical ambients, OEM recommendations of GL5's in 80W90 and SAE 90 viscosity grades is akin to recommending mineral oils specifically ......
and that seems to apply in UK, IMHO.
A SAE 90 grade has a [email protected]
*C ranging from 135 cSt to 224 cSt pre-2000.
A fully synthetic 75W140 typically has a [email protected]
*C of 170 cSt, and could be an alternative in your case.