Best gear oil for Viscous differentials?

[MaDMaXX]

I was looking at Redline Shockproof and their normal 75w90 gear oil, i need a GL-5 based gear oil.

I've read that the GL-5 spec is more suited for limited slip applications, but i wanted to know if any were particularly suited to viscous type LSD's or indeed are not suited to them?

Thanks.

 

[aquariuscsm]

Is this for your Z? Mine specs 80W90,so I`m using Amsoil AGL GL5 80W90.

 

[SubLGT]

A viscous coupling in a differential is a sealed unit and requires no special gear lube.

 

[brandini]

Originally Posted By: SubLGT
A viscous coupling in a differential is a sealed unit and requires no special gear lube.

+1

The unit that does the work in the diff in indeed sealed. the fluid is simply to transmit heat and protect the large metal parts. (ring, spider...)

 

[Ken2]

Originally Posted By: MaDMaXX
I've read that the GL-5 spec is more suited for limited slip applications,
You read wrong. GL-5 is the spec for a gear oil suited for hypoid gears...spiral bevel gears where the axis of one gear is on a different axis of the other gear. This results in a great deal of sliding motion of the gear teeth, and GL-5 species an additive package to allow the sliding without gear tooth wear. It does not relate to limited slip.

http://www.upmpg.com/drivetrain/gearlube/hypoid_gear.gif

 

[MaDMaXX]

OK, so it's an internal internal thing, that being said what's the gear oil to get? i' guessing it doesn't have to be too specific.

It is for the 350z, does anyone know what type of gears it contains?

 

[rpn453]

They would be hypoid gears. Any 75W-90 or 80W-90 GL-5 will be good. I'd go 75W-90 for better fuel economy and cold temperature performance. Use whatever brand you have confidence in.

 

[MaDMaXX]

Yeah it specifies 75w90 and it will be run in the cold, so looks like i could just pick up some castrol or amsoil perhaps.