[280zxDat]

Okay so I have seen a few post over this but they all seem to be a little over the place so I thought I'd ask about what I found here. I have a 1983 datsun 280zx non turbo. Just rebuilt the transmission and now need to decide on what oil to use. In my research I read to replace the differential oil at the same time. (If this matters or not I am not sure. My differential seal is leaking so I'm going to do it anyways to change the gasket). I was just curious on what oils and viscosities to use. I know that gl4 in the transmission and gl5 in the differential. From what I have gathered Redline gl4 MTL 75w80 is what to use in the transmission and Redline gl5 75w140 in the differential. I live in Texas btw so it's always humid and hot. Thoughts on my conclusions?

 

[pilgrim]

I've researched this for the 5-speed transmission in my 1983 280ZX Turbo.

Depending on the site you look at, there will be recommendations either for automatic transmission fluid or gear oil. I have always used gear oil in mine (32 years now).

There is a discussion of this point on Hybridz.com: Dexron ATF on the BW T5 :)

And that includes this spec sheet from the service manual:

There is also an article from Hemmings about the T-5 which doesn't give much info on the Datsun cars but makes an important distinction between the generations of T-5 transmissions referred to as NWC (non-world-class) and WC (world class.) The Hemmings article indicates that the WC units use Dextron ATF because of the needle bearings. Non-WC units like the Nissan are spec'd to use gear lube. I use Mobil 1.

https://www.hemmings.com/stories/article/borg-warner-t-5-trans

I have always used GL-4 synthetic gear oil in my 1983 ZXT.

 

[bonfire79]

Just use what's in the book (factory service manual) as listed above^^^^^^^ and you won't go wrong.
whatever you do, don't follow the idiots on youtube that haven't read the FSM and are just pouring fluids in cars they truly have no idea about.

Bon

 

[pilgrim]

Yep, it's clear that the manual transmission in the NA model takes GL-4 gear oil.

That's another important point: GL-4 in the transmission. GL-5 in the rear differential.

That protects the synchros in the transmission.

 

[Bart73]

Okay so I have seen a few post over this but they all seem to be a little over the place so I thought I'd ask about what I found here. I have a 1983 datsun 280zx non turbo. Just rebuilt the transmission and now need to decide on what oil to use. In my research I read to replace the differential oil at the same time. (If this matters or not I am not sure. My differential seal is leaking so I'm going to do it anyways to change the gasket). I was just curious on what oils and viscosities to use. I know that gl4 in the transmission and gl5 in the differential. From what I have gathered Redline gl4 MTL 75w80 is what to use in the transmission and Redline gl5 75w140 in the differential. I live in Texas btw so it's always humid and hot. Thoughts on my conclusions?

I changed both fluids this summer in my ‘82 non-turbo. Used Redline. GL4 in the tranny and GL5 in the diff Based on mfg specs. Seemed to work very well.

 

[BigD169]

Yep, it's clear that the manual transmission in the NA model takes GL-4 gear oil.

That's another important point: GL-4 in the transmission. GL-5 in the rear differential.

That protects the synchros in the transmission.

You’re right