D35 chirping/squeeking around turns?

The old '88 just started squeeking around turns. Left and right turns- coming from the back end. Doesn't really do it going straight. I only notice it at low speeds on 90* or more turns.

It is not a constant chirp, but a pulsing one like something is rubbing in one spot as the tire rotates.

What should I look for? I'll probably put the back end on jackstands and wiggle the wheels around- not really sure what else to do.

Put in new fluid about 2 years ago. No leaks spotted since then. Brakes are new as of 2 years ago too. I think they are working as normal.

Any guesses?

Thanks

well it sounds like its a fully locked dif but if not then the bearings cud be going out and leting the shafts bind up on sumthing.

As far as I know it is an open diff. Also, the chirp is not a tire on pavement chirp, it is a metal on metal or brake rubbing kind of chirp. I guess you might call it a squeak.

pop the rear cover off sounds like the bearing shit a brick

Is there kind of test here? How can I check the bearing and how hard is a replacement?

Thanks