I have 2nd gear slippage on my, recently bought, 240Z. 1st and third gears seem not to slip. Please tell me if there is an adjustment to correct this. I recently installed an oil cooler; could this have caused the slippage? The oil level seems OK, but I'm still confused on how to check it. I was told that to check the AT oil level I should run the car; then turn it off, wait 15 min; then check the AT level with the car engine Off -- is this correct? Thank you