Hey guys, silly diff fluid question. Getting ready to do some diff maintenance and had a question about fluid. I'm pretty positive I don't have LS. At least there's nothing on the rear diff stating as much. The only gear oil I had at my local shop was valvoline 80w-90(which I know I need).

The small 1 quart bottle says limited slip which makes me think the additive is already added? The larger 4 quart bottle does not but I believe they're identical. As far as I know even if the additive is present it wouldn't do any harm correct?

Also the valvoline says it's good to go for gl-5 applications.

I attached photos of the diff plate and oil to double check everything above

That is a good choice of gear lube, and you are correct that presence of a limited slip additive won't harm when you don't have one.

I just filled up my front and rear axles with that exact oil this morning. Good choice. Like Jerry said, the limited slip additive won't harm anything.

It does say "Recommended for all hypoid differentials (conventional and limited slip) ...", though.



No harm in using it in a non-limited slip diff.