[KensRedZed]

Hi Chris,

Thank you kindly for the suggestion. I didn't test any of these cars without oil. I was pre-warned about the armature scream. I skipped the thin stuff and started with a medium viscosity grade oil. Then moved up to a light grease for RC boats.

It was suggested to test all the motors without the idler gear to look for armatures with the least vibration. The lubricated armatures all spin up perfectly smooth without the floppy idler in place. Once the idler goes back? The screaming instantly starts up again.

Here are some quality control issues I can easily see with the naked eye.

1) Some of the front axles are binding in the chassis. The front wheels aren't rotating smoothly, or at all.
2) Some of the crown gears can skip a tooth on a new car straight out of the box. As if the crown was made a bit to thin to provide a proper mesh with the pinion.
3) The armature shaft is flopping around a bit loose in the lower chassis on a new car. Like the chassis hole was made a bit too large for the shaft.
4) Every idler gear flops back and forth on the post that holds it in place. It wobbles back and forth very badly between the drive, and driven gears.
5) Most of the stub shafts that hold the gear to the crown, wobble badly too.

I bought more than half the cars new in boxes years ago. But could not test them. What a mistake.

I don't think a lack of oil is the problem here. I got the crap no one else wanted to buy. These new cars were only $10 each many years ago. Come to think of it. These were new in the box. But the hobby shop that sold them to me, cracked them open already. They probably knew the cars were garbage. I simply bought a nice set of dud cars.

It's highly possible that these were run dry at the hobby shop. They may have screamed before I owned them which might have expanded the hole in the chassis. Every car had spark-marks on the shoes.

I'm glad everyone here has more experience than me with these little cars. I could use a few more suggestions please?

Thank you,
Ken