[SIZE=3]My dryer recently began to squeak so my husband replaced the belt. Nothing changed. Now it makes a very loud and consistent knocking noise. The drum does not shake and it will still dry clothes. A new motor is very expensive, is there anything else that could be wrong?[/SIZE]
A knocking noise is often a bad rear support roller.
May also be something stuck in the blower wheel.
Can also be a split drum (usually at the seam) or bad front glides.