The last time I tried to drive my car I could not drive it past 20 miles an hour with out it jerking violently every time I tried to accelerate but it worked fine i the lowest gear, my brother kept it over night to take it to a mechanic and on his way there it began to get way worse, the machanic didnt look at it untill the next day, but by that time he did it worked fine again, and he had no answers. it has done it twice in three days. Is my transmission going out?
Maintenance history of the engine?
Maintenance history of the transmission?
Did you check the transmission fluid when these symptoms began?
If yes, what can you tell us about the level, color, and odor of the fluid?
The likelihood is that this is a driveability problem caused by lax engine maintenance, but it is also possible that this could be a transmission problem caused by lax transmission maintenance. If you give us the missing details mentioned above, we may be able to make better guesses.
Scan the computer for codes. This is where you need to start. Take it to one of your local auto parts stores, they will usually scan it for free. Write down the code/s and their descriptions and post them back here. I usually see a lot of input/output speed sensors go on these so that would not surprise me at all.