Would you use 75W-90 as Transmission Fluid

[Jdude1]

I read in my user manual that 75W-90 will work as transmission fluid. What are people's opinions on this? it would be great to buy the same diff and transmission fluids for simplicity but I don't want to risk damaging anything over something as simple as a little oil.

[Towncivilian]

What year G37S do you have? Both the 2009 and 2010 specify GL-4 fluid only in the maintenance section of the FSM. GL-5 fluid can harm brass synchros in the transmission, which likely explains Nissan's requirement for GL-4 The 2009 FSM specifies 75W-85 viscosity, while the 2010 FSM says either 75W-85 or 75W-90 are suitable. I don't know the reasoning behind that, but since the transmission is the same model (FS6R31A) for both years it is logical that 75W-90 can be used in the 2009 MY G37S.

[Jdude1]

I've got the 2009 G37S-MT. In my user manual it list's both. I went my local advance today where a pal of mine talked me out of buying the Moble 1 Synthetic for both my transmission and the Diff. I'll be going to the Infinity or Nissan Dealership this Friday. I did get some information on quantities that I was curious if someone could confirm. He stated that I need 3.1 quarts for the transmission and .7 for the Diff. If that's correct I'll probably just get 4 quarts of 75W-85 for the transmission and 1 quart of 75w-90 for the Diff. My brother the mechanic said that the -90 is just a hair thicker but down here in SC it probably won't be a problem.

David

[Towncivilian]

See MA-10 for the correct quantities of fluid. The front diff requires about 0.7 quarts and the rear 1.48 quarts. The manual transmission quantity differs silghtly depending on your VIN and options.

Mobil 1 75W-90 will be great for the diffs. Be sure to order online, use discount codes and pick-up in store if you order from Advance Auto, you'll get it quite a bit cheaper.

Redline MT-90, Amsoil MTG, and the factory Nissan fluid are all good options for the transmission.