check the U joints. they will make many sounds when begining to fail. cold weather/not using often can cause these to fail . if parked over unpaved surfaces mositure gets into them.
see if the joints are discolored. operate vehicle and see it one is warm or hot compared to the others.
with the transmission fluid. when adding additives to aid in the transmissions performance it is best to replace the fluid shortly after. these products help remove deposits in the torque converter and the many valves/passageways. use the new dexron VI. do not use dexron III.
If you over fill use a hand held pump that is for pumping from an oil container. use a hose about 3/8 dia 4 ft long and stick into the fill/dip stick tube . I have a clear hose on my pump and this pump also fills the diff/transfercase / and my mercrusier outdrive..
on your transmission at the fill mark you can suck out about 1qt...