W116, Rust Repair

This is about window regulators, specifically on my 1980 300SD (W116). The drivers side window regulator is broken, and MercedesSource has a new replacement for it, but no instructions available with the new part. After examining the broken regulator, I believe that a lack of grease (or lubricant) on the regulator slides contributed to the failure. Further, my other windows are moving slow or binding up, and I suspect that lack of lube is responsible for that slowness as well. Trouble is, I don't know what grease to use on the regulator mechanism. Grease isn't just grease. It's formulated to work at a certain temperature, under specific conditions, and I'd bet the grease on a window regulator is altogether different than wheel bearing grease, for instance.