Urgent - gearbox oil

[Navaranugget]

Hey guys , today I'm changing the gearbox oil in my
1991 2wd nissan navara d21 nugget with the 4 speed Manuel
Gear box and I'm unsure of what oil to use I heard that you can't use GL-5
And heard you can , so do I use GL-5 or GL-4

Thanks

 

[sparra04]

Go to valvolines website
put in your car details
all lube details are there

 

[Pepe]

I always use an 80W-90 for my Nissan DT21 box in my 4x4. As these gearboxes are not strong I feel having a thicker oil is better for these older gearboxes. However up to any other thoughts on this??