Latest fluid recommendations

[Rut]

We are about to button up this Bugeye/Datsun project and I recommended VR1 20w50 for the engine oil and I have some leftover Brad Penn GL4 for the diff, but what’s the latest on lube for the Datsun 5 speed? I see a variety of suggested products for both the tranny and diff, but I would like the latest scoop.
Thanks, Rut

 

[Joe Schlosser]

Redline MT 90. IMHO best for all gear boxes

 

[Rut]

Joe,
For both the tranny and rear end?
thanks, Rut

 

[Joe Schlosser]

Rut
I never have used it in the reat end only gearboc
The Name is confusing as it is not 90 weight grear oil.
The container says transmissions

 

[twas_brillig]

I use 1.2 litres Red Line MT-90-GL-4 in the Datsun 5 speed transmission (also the Spidget 4 speed), and Red Line 75W90 GL-5 gear oil in the Spridget differential. For the steering rack, it's Royal Purple 75W-140, and Castrol ATF for Armstrong shocks (per AH Spares). For the engine, I've been using Castrol Edge but may switch to Rotella 15-40 T4; we use Valvoline VR-1 in a turbocharged BMW 2.5 litre that is stuffed into a 1972 2002. All of these (plus others such as Mobil 1 15-50) have the magic minimum 1200 ppm or higher of zddp (zinc dialkyl dithiophosphate). Red Line seems to have a very positive reputation for gears; I don't remember why I picked Royal Purple for the steering rack. I think that trying to understand and determine the optimum oil types and change frequencies for older vehicles is akin to Sisyphus, eternally rolling his rock up that hill. Doug

 

[Rut]

Doug,
Thanks a bunch for all the recommendations!
Rut