Transmisson

I have a 2002 chevy impala 3.4 and a few months back I replaced the right axle and now I started to hear this noise like I have new or ****bie tires on a 4 wheel drive pickup and also I lost third and drive in my transmisson and losing tranny fluid and cant see where its coming from expect the corner of the pan but on the left side I noticed lot of oil on the boot and lines also looks like some kind of stop leak I bought the car used so don't know much about it I do most of the repairs myself so please help me