I am a new member and I recently bought a "48" with Fluid Drive. The car runs great but when I let off the gas to let it upshift in both low and high, I hear a faint click but it doesn't shift into the higher gear. It doesn't go into a higher gear but at that point, it is in no gear, I can give it gas and it is like it is in neutral. Then I slow down and it goes into the lower gear again. The previous owner said he found the car with 90 weight gear oil in the trans and he replaced it with 10 weight oil. he suggested maaybe the plunger was gummed up. How can I diagnose this before I pay someone who knows how much to do it for me? I appreciate any help. Also, does anyone know some good mechanics in or around Phoenix, Az. Thanks again, Billyzack