I have an automatic 4 cylinder 2000 dodge neon with what I believe is a transmission problem but i have no idea how to fix it. the car will start up just fine and i can go in reverse without any problems. But if i accelerate start from a stop to quickly my car will shake pretty heavily. then when i reach about 20mph (while the transmission goes from gear 1 to 2) my car will shake even harder if i am accelerating too fast. i talked to local mechanics and i have done what they said but i still have yet to fix it.
So far i have (in chronological order):
replaced the air filter
used an injector cleaner (which caused sparkplug problems)
changed the motor mounts
added lucas transmission fix
lubricated the transmission line

*also when i put the transmision fix fluid i noticed that the transmission fluid level was too high, i wasn't able to drain and fluid out so i only put in about 6 oz. of the transmission fix. could have too much transmission fluid cause the violent shaking.
Thank you in advance