Gearbox Oil

[Sam]

Should I get it from Nissan? or will somewhere like halfords have it?
How much would I need?

 

[sri_alan]

Halfords wont stock it in big enough quantities, they usually just sell the 1l bottles. I just get Comma stuff (probably the same as Halfords own brand) from an independant motor store, comes in 4.5 or 5l containers which is just more than what you need.
80/90 is fine, 75/90 is better/more expensive