I just wondering what kinda of fluid I can use in my s5 t2 diff? Ive been looking and I dont have access to royal purple fluids. I just have and autozone and oreillys.

 

they sell royal purple products just maybe not in your area, Pennzoil synchromesh works great too

 

A stock S5 TII diff is a Torsen type unit, therefore, use a standard GL-4 or GL5 gear oil without a friction modifier. Cheap dino gear oil (non-synthetic) works fine in a S5 TII diff.

 

I can't stand misinformation, especially when it comes from me.

The stock S5 TII has a viscous LSD, it's the FD that has the Torsen. The FD diff is a drop in replacement for the S5 TII and worth it if you want a long life unit vs using a S4 clutch type diff. The conclusion is the same however, any decent GL4 or GL5 gear oil will keep your S5 diff healthy.

Thanks RX7 club for letting it slide.

 

Only use GL5 oil in a diff. GL4 is for transmissions.

 

The type and quantity is specified in the 1989 FSM.
Foxed.ca - Mazda RX-7 Manuals

Mineral oil will work fine in a street car LSD. If you want synthetic oil for whatever reason, then any brand of GL-5 will work. Most likely you will want 75W-90 synthetic. O'Rilley usually carries Red Line, and Autozone usually carries Lucas Oil, Royal Purple, and/or Mobil 1. Your local stores should be able to order some synthetic oil if they do not usually keep it in stock. Otherwise, you can always order it online from O'Rilley, Autozone, Jeg's, Racer Parts Wholesale, Summit Racing, Pegasus, and probably a couple hundred other websites.

 

Not the case, both GL-4 and GL-5 work fine in a S5 TII diff. The second sentence is true though - you don't want to use GL-5 in a synchromesh tranny.