Thinking about changing the transmission and gear oil in my '85 GSL tomorrow. Will the oil in the pic work ok in both? Am I right to assume that since it says "limited slip" on the bottle, that it already has the LSD additive in it? Will the limited slip additive cause any issues in the transmission? Thanks!

 

Should be just fine. There are a few 7 guys on here using royal purple in both tranny and diff. 75w-90 is fine. I use 80w-90 in the tranny and diff. You could also run 50/50 atf/gear oil in tranny if you want.

The additive is already in there. If you still got diff chatter I would just get lsd additive and add it in.

 

Most gear oils these days will have the LSD additive. Wont hurt your transmission at all! Go for it!

 

I've found the easiest way to add oil is to stick a hose in the fill hole and have the other end come out of the engine bay. Since most tranny fluid bottles have a nozzle at the end, put that in the hose.

 

Thanks guys!

 

I've been using that oil in both for a few years now. Works great. Still looks good
last I checked it as well.