Unbalanced front tires could cause your steering wheel to shake, unbalanced rear tires can cause what you're describing. Also, it's much cheaper to balance your tires than to go tearing apart your diff. I've also never heard of balancing a diff... if your diff is junked you'll hear it.

 

yeah there is no diff balancing IIRC.

your rear end is about to go if you hear a noticeable and audible whine and clunking.

 

and welcome!

 

welcome

 

ah okay, makes sense. yeah I was driving on the interstate and noticed it instantly. definitely will get my tires balanced