this may be a stupid question, but I am learning as I go here..
I changed my front diff oil the other day, and now today doing my rear..
the rear looked much better than the front. Front was black, rear still brown.
I just noticed, the oil I bought, Valvoline 80/90 says limited slip on the bottle..
I know some require additives..
My question is, does limited slip mean it has the additives? And if so, what if I don;t need additives, will they hurt anything? I know if you need them, and don;t have them you can booger things up. But what if you don't need them?
This whole thing has me scratching my head. Just need clarification..
Thanks..

 

If the bottle says Limited Slip then it probably has "friction modifier" in it. If you have a limited slip Diff you need friction modifier. If your diff is open it won't hurt to put it in, but it won't help either.

 

More head scratchin'....the additive will hurt nothing and it may not be needed, even in a limited slip diff. If there's no chatter/noise from the LSD in a slow/tight turn, the additive is not need. The additive allows the LSD clutches "slip" easier for less/no noise/chatter. Kinda dumbs down a traction enhanced diff but some folks demand smooth/quiet.

 

Alright..
So wont hurt if you don't need it.. But mandatory if you do.. Cool.. I think we are all good then..
I have no idea if I have limited slip or not. So I guess it wont hurt nothing to use it. Just in case.. It was only $5 a bottle. Same price as the others, actually cheaper.