1994 Geo Prizm Geo Prizm clunking while driving slow

Hi, my 94 prizm is making a clunk, clunk, clunk while driving slow. The sound doesn't seem to speed up or slow down as you go faster or slower. As a matter of fact once you go over about 25mph it stops making the noise. I thought the CV axels might be worn out and they were so I replaced both and while it did help the drivability it didn't eliminate the noise. I was checking under the car to see what I could see and no wheel bearings or control arm seem to be loose. Could this be my differential bearing gone bad. I jacked up the front of the car and put it in drive so the wheels could free spin. I didn't hear any noise but where the CV axel comes out of the transfer case it seems like it's wobbling a lot. Any ideas would be much appreciated. If it is in the transer case/differencial can I get replacement parts for that easily?