Those DRY nylon front ball joints.
Can you inject grease into them ? They sell a needle with a grease gun nipple at the end to inject grease into rubber cup that keeps dirt out. I would think that grease would not degrade the nylon (or whatever plastic) ball and socket (maybe the ball is metal and the socket is plastic-I don't know) I would think that if grease can keep metal ball joints from wearing- why not grease those unserviceable GM ball joints. If regular grease degrades the nylon, do they make a grease that doesn't degrade it?
Can you get aftermarket ball joints with a grease fitting on it?