Running into a slight problem... Trans is starting to have shifting problems. rpm holds a 2k for a while then shifts. trans has 145,000 miles. I am trying to figure out what fluid i can run instead of toyota factory, something a bit thicker? I am running 295 75 all terrians and i know this will not help my problem. Gearing would be ideal, but as of now i can not afford that cost. Any recommendations?