Hello,

I am changing my 6spd transmission and differential oil. I see some people are using the Shell Spirax 75W90 synthetic gear oil in transmission and differential oil. This oil is rated GL-5 which isn't compatible with the 6spd transmission (GL-4 needed). However, there has been some talk that the Shell gear oil is copper friendly. To those who are using this product, how does the transmission feel compared to the OEM fluid? Is this safe for our transmission? How many miles have you put with this fluid?

Also, do all G35's have LSDs in the differential? Is any friction additive needed?

I would like to hear your opinions. Thanks.

 

i just went through all this. all 6spd models have the LSD diff.

use the GL-4 in the tranny, not an oil that claims to be both. use GL-5 in the diff.

i used pennzoil synthetic gear and tranny oil, with no additional friction modifier for the diff.

 

Thanks for your reply. Will Royal Purple Max Gear 75w90 work? On there website it says it is both GL-4 and GL-5 compatible. Anyone who is using it want to confirm?

 

iam getting ready to change mine as well i am thinking about using royal purple as well

 

could someone please link up a GL-4 product? I want to change mine before winter comes and I cannot afford to screw up a tranny!

 

https://www.amsoil.com/storefront/mtg.aspx

 

http://www.pzlqs.com/Tech/Pdsheet/Do...E75W90GL-4.PDF

Pennzoil Synthetic GL-4...