Automatic transmission slip
Why does all most all used cars I have owned in the past has or will develop a slip in when changing gears. Specialy when changing from 1st to 2nd. I'm aware about things like proper maintenance, changing filter and using the OEM recommended oil will help. I just need a proper way to fix this without taking the gearbox out. Will thicker additives like lucas would help. Does a lose timing belt, junk in the intake system, bad plugs, injectors, coils, mounts or anything else would relate to the car hesitating to change gears or make a vibration when shifting gears. Thank you.