I have a Zexel Torsen LSD and am going to change out the gear oil. Im going to put in Royal Purple 75w140 synthetic lube. Any one disagree with this?

 

buy the LSD additive from the dealership, trust me on this.
if your rear has any problems that are being masked by the stock thick fluid then they will be amplified by the better fluid. I ended up having to replace my ring and pinion.

other than that, I love having all my fluids from to. Zero regrets.

 

The standard OEM 99-02 Torsen didn't have any friction surfaces that would benefit from the limited slip additive.

There was an aftermarket T-2R with bias friction setup (cones IIRC + the torsen assy.) That would need additive.

The '98 year had a Torsen as optional; I don't know if it was the T-2 or the T-2R.

75-140 isn't going to benefit you on 99% of street cars; 75-90 is fine.

 

Yep, ZT posi doesn't need additives. Normal Gear Oil will work fine.

 

I didnt know that it doesnt need any additives, good to know. The main reason im going with Royal Purple is ive got a bit of gear whine from the guy who installed it incorrectly. when i was able to get it back to him, the gear pattern was already set. so i was hoping this would quiet it down maybe just a lil bit till i get new gears put in. and its time for a fluid change anyway.

 

Running RP gear oil in my Z28 with no problems.

 

might want to read this
www.synthetic-oil-tech.com/Gear Lube White Paper.pdf