I'm not sure if this will help many people here or not, but figured there must be owners besides me that are in the same situation.
I realized after buying my 90 that the visors wouldn't budge. My first thought was to check the usual vendors for a replacement. Turns out they are more or less NLA. (I didn't know that acronym until I owned an NAS Defender.)
Mine looked fine, but the arms were frozen in the sleeves, so I decided to see if I could loosen them up.
- Spray Seafoam Creep, Liquid Wrench, etc into each sleeve where the arms enter. Let them soak a few hours.
- Place the visor on a bench with the end of one arm over the side.
- Place a board on top of the visor so you can hold it still.
- Clamp vice grips with a rag or other padding on the flat art of the arm and and torque away up and down.
- If the arm doesn't give or starts to bend relube and give it more time.
- If the arm is moving start pulling it out while turning. The two arms are separate and can pull out.
- Clean the arms and soak in Ospho or something similar. I also sprayed cleaner into the sleeves.
- Grease the arms and reassemble.
Seafoam Creep was also used to free up my passenger side door latch, seat belt buckle, dash vent handles, heater controls...