Headphone Jack low volume, yet speaker works fine

The headphone jack volume is very low. Without headphones in the jack the volume and sound is fine. I've found if I position my finger on the bottom iPod where the headphone jack is located and my thumb on the top of the iPod and squeeze the volume is at a normal (loud) level.

Can this be fixed? Could something be placed in underneath to create this finger/thumb pressure?

It appears to fully remove the headphone jack to be pretty involved.

Thanks.