+2 for the diff oil change, and thanks for the reminder, mines due. I also have light intermittent clunk on takeup.
Syntrans is pretty much all in with FM additive
https://www.eurocarparts.com/search...Yg8q2TMGP2GuiQiK4Bm1XJN36VRoCsR4QAvD_BwE, available from other outlets.
I'm using MTF94 which I buy in 5l, with redline FM, but I'm likely changing diff oil every 18 months or so.
https://www.googleadservices.com/pa...bxAhXRfMAKHfxnAL8Qwg96BAgBEBc&adurl=It's worth doing the gearbox at the same time, unless it was changed at last service/<25k miles.
