Let's talk fluids: Redline 75w90 vs 75w90NS

[IIv SHaDoW vII]

I'm in the process of doing a complete fluid flush and refill and I have a few questions about the tranny, t case, and rear diff fluids.

My profile is up to date.. The car is a 98 GSX.. all major components are stock except for a big 16g turbo.

Here are the recommendations I received in another thread. I'd like to know if using the 75w90NS provides any benefits over the 75w90.
The provider of this info recommended Redline.
2.9qts of MT-90 GL4 (75w90) in Transmission (another thread stated 2.4 qts; typo?)
0.5qts of MT-90 GL4 (75w90) in Transfer Case
0.9qts of MT-90 GL5 (75w90) in Rear Differential

So which fluid is better? NS or non-NS?
Also, I read in another thread that the NS fluid is only to be used in the t case and rear diff.. not in the tranny. Can someone verify?

Lastly, I am not 100% set on Redline.. I am open to other recommendations..

I am leaning toward just going with 75w90 all around and not using the NS stuff at all.. but I'd like to hear thoughts.

Cost is not an issue for these fluids. I am also open to other recommendations.

 

[synthetek]

I use MT-85 or 90 in the trans and Heavy Duty Shock Proof in Rear Diff and T-Case. Most of the major trans builders recommend Heavy Duty Shock Proof For the Rear Diff and T-Case and MT-90 / 85 or The OEM Diaqueen EVO IX fluid in the transmission. Its 2.4 Qts for the trans.

Also, I read in another thread that the NS fluid is only to be used in the t case and rear diff.. not in the tranny. Can someone verify?

The NS is GL5 , GL5 is usually not good for transmissions with brass synchros but redline says theres is safe "Safe for brass synchros, as it lacks the reactive sulfurs found in most GL-5 oils that cause damage" but I wouldnt use it.

 

[IIv SHaDoW vII]

You use heavy duty shock proof in the stock transfer case and rear differential?

Also, it's not listed on the heavy duty shockproof whether it's GL4 or GL5.. the recommendations I received above were GL4 for xcase and GL5 for rear diff.. Is it ok to put this stuff in both with no issues?
https://www.extremepsi.com/store/product.php?productid=18981&cat=267&page=1


Also, is this mix of fluids (MT-90 in tranny/ heavy shockproof in xfer and rear diff) ok to use all year round? I live in Kansas so the winters are COLD, and the summers are HOT.

 

[synthetek]

Yes, Heavy Duty Shock Proof is what everyone I know uses in there stock Transfer case and rear diff and and what all the major trans builders reccomend, Jacks, Shep, TRE. Go check out there sites and read their fluid recommendations. It does not say on the bottle if its GL4 or 5 but search for some other threads about it on here, while there seems to be a lot of opinions on what to put in the trans it seems like most people agree on the Heavy Duty Shock Proof for the Transfer case and rear diff.

 

[IIv SHaDoW vII]

And you run straight heavy shockproof all year round?

Around here, it gets as low as -10 degrees during the winter.. I just want to make sure I can run this stuff all year round.

 

[synthetek]

And you run straight heavy shockproof all year round?

Around here, it gets as low as -10 degrees during the winter.. I just want to make sure I can run this stuff all year round.

I run it all the time and have for years but it does not get anywhere near that cold here.