Drifting Windshield Wiper park position.

[Bernie Benz]

Does anyone have any BTDT on correcting the subject problem?  Within a
relatively few minutes of wiper operation in the intermittent mode the park
position moved slowly up the windshield to the center area.  I am assuming
that the park switch cam in the motor has come loose from its correct
position on the output crank shaft and has moved to a new park position
relative to the wiper sweep.  Apparently I must remove the motor and
disassemble the parking switch system.

Bernie