Which transmission? I'd recommend dropping the pan and inspecting the fluid that drains out. Look for discoloration, a burned odor, and debris on the bottom of the pan from clutch wear. Also change the filter while you're in there. Since it's been a lot of years since torque converters were equipped with drain plugs, only slightly more than half the total volume of fluid can be drained that way. Other than the above drain and inspection, there's really no way to do a function check without running the engine.
Jerry
