check the transmisson fluid level is correct and no leaks coming from g/box or surrounding areas, driveshafts etc, if you find a leak, fix this, and after putting in correct amount/type of fluid, start the car and keeping the brakes ON, move the gearlever thoughout the gears, to allow the fluid to settle though the gears, and try driving the car, if problem is still there then you need the help of an auto trans techie, but it wont be cheap. Good Luck.
hope it helps, November 2010
