Where is the dipstick for tranmittion, dont have a manual and cant find where we are losing water

There isnt one. there is a screw with a hex head on the rear of the transmission just above the transmission oil pan. when you take out the screw the oil will just start to drip out. to add trans fluid on the drivers side under the hood you will see a large black tube that comes off the engine. look just below that down into the engine toward the ground and you will see a red cap about 2 inches in diameter it says transmission fluid on it. you just unscrew it. you will need a long funnel or you will spill