Toyota Repair: 84 Toyota Tercel SW 4WD Front Diff Noise?, toyota tercel, hub problem

Question
I have an intermitent noise when I turn left on or around the right front wheel. Some times the noise would occur when I turn right as well.

The Tercel has 140000 and the half shafts replaced about 20,000 miles ago.

The mechanic says it is the Differential which could cost 4k to fix (worst case). Their reason for making the diagnosis is the up and down play in the axle at the diff.

They say it is very common with these cars. I am getting a weird feeling about this. I will be getting a second opinion but how do I know what they are telling me makes sense. There comment was that this is very common yet I have not found another comment about this on the web.

Thanks a guy who loves this car but can not afford 4k to fix it.

Answer
The up and down movement of the axle shaft in the differential is normal, it is more likely that there is an axle bearing/hub problem, I recommend that you get an opinion on this from a toyota dealer, a differential problem will cause a whining noise and is not related to turning of the car, the noise will be there all the time even when driving straight and would change in pitch depending on vehicle speed.