Rear diff. additive?

[radwulf]

I got the list of maintenance performed on my 1999 4Runner before it was sold to me. It looks like after changing the diff. oil, they put in some unspecified additive in the rear. The truck has the rear locking differential. Could this mean they mistakenly treated it as a LSD type of differential? Could the additive be a problem in the non-LSD / locking diff? Any input would be welcome.

 

[p nut]

Don't know what they put in and if it would cause a problem, but as simple as it is to change out the fluid, I'd drain that thing ASAP and put in some fresh fluid.