Dryer appears out of balance

My dryer runs very smooth at times and then it will start to make some clanking sounds and it appears to be out of balance. What are the possibilities?

Thanks

 Dennis

The rear bearing assembly fails regularly on these.

Here is the part

AP2142648

Take off the rear access panel and release the belt. Then insert a screw driver in the gap between the top and front near the edges to release clips and flip up the top. You can now take off the front, lift the drum out by the belt and repair it.

I would replace the belt and pulley, and make sure you clean everything out, thoroughly!