GL-4 Gear lube?

[RyanBrown]

So from what I have read on here most of y'all feel that the GL-5 gear lube is no good for these 1st GEN transmissions. I have looked at two different stores and can only seem to find the GL-5 gear lube. What the difference between the two and why do y'all say not to use the GL-5? Thanks

[Jrjones]

GL-5 will eat soft metals. In regards to our transmissions, that means it dissolves the syncros (brass I believe).

GL-4 is safe to use. Unless you feel like have a transmission without syncros down the road....

[chainsaw]

It's not a belief, it's a fact. Amsoil sells gl4. It's a little spends but you can run it a long time.

[Rollingcarshopaz]

Yep you need GL-4, it is not corrosive to yellow metals like GL-5. Only thing I could find readily available at parts stores is royal purple

[FitzIngarage]

Your Nissan Dealer will likely have GL-4 locally too, though it won't be attractively priced.

[RyanBrown]

I found a GL-4 gear oil at a local auto parts store. Don't know if it is a suitable gear oil. If it isn't I will def change it. I ended up buying Gl-4 140 gear oil. It seemed a little thick when I put it in. I also added about 1.5 QTS of Synchromesh gear oil. What do y'all think?

[JSutter]

Redline MT90 75w90, MT85 75w85, or MTL 70w80
Amsoil MTG 75w90
Sta-lube 85w90 @ NAPA

I've used all but the MT85 in my 98 5spd Maxima. The Sta-lube is super thick in comparison but its cheap and works in a pinch.

[chainsaw]

Might make it shift a little stiff but oh well.