1995 caravan front-end shake (210,000 miles)

This car rolls smoothly at all speeds when not under load, eg.: 1)coasting down hill 2) not accelerating 3) not pulling up hill. At any speed this car will shake up into the steering wheel and feet when gas is applied, and is variable with the amount of gas applied. When this happens, I visualize a CV joint grinding itself up. But, to confuse the picture a little, When I acquired the car (180,000 miles) It had another shake: between 38 and 45, when it was ready to go into overdrive, it would shake with a banging feel. I changed the transmission oil and filter, and added anti-slip fluid. This shake has abated, but the current shake emerged into sight as soon as it did. Have I overlooked any other possibility?