2002 dodge gran caravan es 3.8

check the fluid level.

Read the trouble codes. Otherwise you're flying blind

your tansmission is dying

you need to replace the tranny

I am sorry you are having this problem. There are a few things we will have to check. Start with your oil and pull the oil stick and see if you have oil up to the line. If you don't add more oil into the engine at the oil cap on the engine. Next check your air filter and see if it is dirty. If so replace it because your car cannot breathe. Next check your fuel filter. These things I told you to check are immediate things you can do to start your car and keep it running. You probably need a tune-up. Have someone who knows cars do the checking with you. Good Luck

The transmission is probably shot. the only other thing could be dirty linkage if you mean "hard" as in hard to move the shift lever. The first thing I would do is get a tranny fluid and filter change.

IT IS CAUSED BY ENGINE BLOWBY(COMPRESSION GETTING PAST THE PISTION RINGS)KEEP CHANGING THE PCV VALVES IT IS MUCH ,MUCH CHEAPER THAN REBUILDING THE ENGINE

replace the input speed sensor to transmission and the wiring pigtail all are available at your chrysler dealer take your vehicle registration in to the parts counter so they have your vin # to get the right part and it is the front of trans by fluid linres to radiator.

When was the last transmission tune? If you just had one and it wasn't at the dealer all the internal computer values will be off. The same happens as fluid wears also. If you haven't, get the fluid and filter changed, make sure the dealer performs a "quicklearn" on the transmission, this will relearn all the fluid volume vlues and shift points. This is a process which any dealer should perform when they do a trans tune. Hope this helps, if the problem persists, you may have internal damage, but what you are describing sounds pretty simple if looked after right away.
Cheers

a transmission flush is a good place to start