so i bought a xt6 a couple weeks ago and the gearbox on the wiper was broke... picked one up today from the wrecking yard. I'm gonna take it apart(really simple actualy already did it once)and clean it, replace the o-ring were the wiper arms meets, and use some silicone to seal the outside of the case. not sure what i should replace the old nasty grease inside with, anyone have an idea?

White lithium would be my choice.

i've done a few over the years and just used high temp/synthetic cv/wheel bearing grease.   it simply needs something - they're really low key gears that simply need something.  i think every one i've ever removed in the past 10 years has basically had nothing, caked up gummed residue of what used to be grease 20 years ago.