Two ways with lsd. In one the additive needs to be added separately to standard diff oil but the more common way is to buy lsd oil with the additive already in the oil. If it chatters you can add more additive
Sanding your knuckles before starting work can help. That way you cant skin them
according to my book the lesser 90 grade is good to 30C. It may not be that hot very often in Wellington but it does get hotter in other parts of the country ie where you live. You should get away with 85w90 but 85w140 adds piece of mind
Sanding your knuckles before starting work can help. That way you cant skin them