My 1987 Toyota 4Runner was sitting for 14 years before I restored it and brought it back to life. Now I'm dealing with all the maintenance issues that are popping up. The latest is the Power steering pump. Its starting to make a whine noise. Not loud enough to worry about but I figured now is a good time to change the fluid and put some synthetic in there. Who knows whats in there now and its probably the original fluid. It takes ATF, and according to the factory service manual Dexron I or Dexron II. Initially I was thinking Mobil 1 Synthetic ATF because its available locally. But would a thicker, higher viscosity fluid work better? I hear Redline and Amsoil's Universal Power Steering fluid is rated as Dexron I/II and is a bit thicker. Any good recommendations?