KTL says.... " The original ones were plain steel with no bronze or teflon liner. Over time they got loose & squeaky from dirt contamination I suspect. In hindsight I should have used teflon lined ends because they are typically a bit more durable. Either way they wear out- bronze wears down or teflon strip gets hammered out from repeated loading and dislodges. (i've seen this same condition on 935 rear spring plate rod ends)..."
If steel....and presumanbly a bit more durable long-term than naked bronze or teflon-lined....you may want to get heim-joint-end- "booties" that are available. Like the kind you can use on the spendy bump-steer kits rod-ends.
Like from "Seals-It"--->
Seals-It