For changing Differential gear oil,

[xagna]

Does rear differential use same gear oil as tranny?
If not, what kind of oil should I get?
I use GL-4 redline MT-90 and can I use this on a differential too?

[upSLIDEdown]

No, the diff uses GL-5. FSM calls for 80w90, but I use 75w90 Mobil 1 Synthetic. Most companies that make a synthetic only make it in 75w90. That's not to say YOU have to use synthetic, I just prefer it since it's only a few bucks more.

[S13 Charlie]

If you have a Kaaz LSD, don't use synthetic, but if you still have the stock open diff, or a VLSD, go for synth. Although, regular fossil oil will work just fine for any open diff.

[Dousan_PG]

open diff? use vegitable oil..water, who cares. its useless buy the CHEAPEST you can for open diff
vlsd maybe a bit more expensive but not much.

[2JZGTE]

80w90 gear oil in my S13 viscous. It cost $3 a bottle I think, works great.