Nismo 1.5/2 way clutch type diff

[WeyounDS9]

I just aded a Nismo clutch type mechanical rear LSD to my SR powered S13.

It comes with a bottle that says "synthetic Nismo diff fluid."

Guidance for my vendor is to use non-syn Pennzoil Gear oil (I forgot which viscosity he said),this non syn guidance comes from Nismo and other blue-chip Nismo vendors ( McKinney) seem to echo that.

BUT the original bottle was a "full- synthetic"?

Anyone here is firm on the theory and practice of clutch type mechanical rear diff.

(Not that it will make a difference but mine shipped as a 2 way and was ainstalled with a 1.5 way set-up.)

Fred..

 

[unDummy]

Use a synthetic. I'm betting that any of the xxW90's weight will be perfect.
But, you might want to use the xxW140's (depending on your power level).
Add LSD additive until you are happy with the "feel" of the rearend.
Some gears oil will need none, others alot.