I need to fix a noisy lock drive motor. I suspect the linear actuator to be sticky. Both nut and lead screw are made of some technical plastic (PA66 if I recall correctly?). Could somebody recommend me a matching lube for that application? An ideal lube should be long-lasting and won't swell nor degrade plastic parts.
The best lube for these types of parts (at least what I've always successfully used) is white lithium grease. It works great for this, window slides ... well, there are a lot of uses in automotive. It will not deteriorate plastic or rubber parts (to my knowledge) and won't cause them to swell. You can find it at most auto parts stores or other department stores where you'd purchase your oil/filters from.