1992 745 243K

My son's wagon just started this in the past week.

The car starts quickly but as soon as it does there is a very loud screech that lasts less than a second. It is similar too but louder than a slipping drive belt.

I assume it is the starter pinion hanging up and being spun at high speed by the flywheel before it disengages. I guess I am looking for a second opinion or verification.

I assume the fix is to replace the starter? Do you think lubing the pinion might be a reasonable attempt at a cheap fix?

Disconnecting the coil and cranking the engine eliminates the screech.

Thanks!
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Any twenty minute job is just a broken bolt away from a three day ordeal