So my LG dryer (DLE9577MW) is getting up there in age. 15 years old. I replaced the idler pulley and belt about 3 years ago--as well as one of the wheels.

Rather than buy parts and replace and pray, I would like to source the noise first, so I buy right and fix ONE TIME.

I've had it apart, clearly to replace the belt and idler and one wheel. So I know what is inside.....what puzzles me is this noisy squeak--and it is loud--starts out loud and after about 1 or 2 min, gets softer and softer until it eventually is gone.

Some would say get over it cause it doesn't last the entire drying cycle; however, the initial startup squeak is so bad you want to leave the room. Note it isn't a constant noise like a bearing is going out (Grinding) it's a squeaky bounce, if you will. It changes as the tub rotates.

So what are my options:
Idler pulley
Dryer Tub wheels (2)
Is there also a bearing in the motor that could be failing?

Now how to determine which of these--without buying all 3 and throwing money at it to hope I solve it and then have to pay to return unused parts.

Thoughts?