serious problem w/ 88 deville

Ok ive had the car about 5 years now and everything was fine but recently when i get the car up to a certain speed and it goes to switch gears it starts jumping or like jerks. Could it be that i have to get a new transmission or can it possibly be that something clogged could make the car act this way.

I really need help..

Your description of the problem could be a misfire, the trans shuddering or a clogged fuel filter this should be checked and road tested by someone familiar with those year Caddies, really not possible to diagnose this in this environment.