</font><font color="blueclass=small">( </font><font color="blueclass=small">( I would not use a 75-140 in there. )</font>
why ?????? I would think that since the viscosity is less than a 90w gear lube that the 140 would give a better protection... Your thoughts?????? )</font>
It depends on what you use. Synthetic or not. Synthetic will be ok but regular old gear fluid, no. The pour point will kill you with a regular old gear lube. It will be like a rock in New England winters.
Another reason why I say no is that and you really do not need it. It would protect more from higher temps but your front axle will never see those temps or torque loads, friction, etc as it was designed for. If you had it in a truck rear end and pulling cars or boats yes but a BX, it is overkill and not needed (I feel). I will not hurt anything but the
75w-90 would be more then adequate.
Lastly, when I installed the 75-90 2000 fluid it only took I think around 2.7 qts. So now I have 3 extra quarts now. Manual stated 5 if I remember correctly.