Im just getting around to giving my car a good once over maintenance wise and noticed the the passenger side cv shaft seal is leaking. I was going to check the diff fluid but the biggest socket i have it a 22mm which is too small. Does anyone know what size the fill and drain hole plugs are on the rear diff?

Also i have a bunch of royal purple 75-90 (for limited slip) sitting around. I was wondering if i could safely run it in the diff? ...since the shop manual calls for straight 80w or 90w.

And my last question... I was checking wheel bearings and suspension components by grabbing the tire (off the ground) at the top-bottom and left-right sides to check for any play. I did notice some play from left to right but nothing up or down. It is also accompanied by a slight popping noise but i can not tell where it is coming from. I belive it may be the to adjustment link but could use some advice in diagnosing the issue.

Thanks for any response in advance!

 

fill plug is 24mm, drain plug is 23mm.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/changing-differential-oil-giving-up-need-help-913467/