idler rumble, heat, and record wear--a connection?

Lew... that was a thoughtful reply. +1

Maybe there's a heat lamp hanging over the turntable.

I'm thinking the massive ply plinth does not allow enough ventilation. Seems like after 1 hour of use when I remove the LP, it's like it was in a warm car. I've had tons of turntables, even a good number of idler drives, but this is my first idler ROK. With the clunky motor, the heat generated isn't so much my concern, its record wear from a warmed, softened LP.

I figured it was motor heat. If it is indeed anything to do with friction in the bearing generating that much heat, it's new bearing time. Maybe the bearing or the ball bearing is toast and the rumble is coming from there.

If it is the motor running hot, replace the capacitor.