Model number is UCVM36FS/03
After removing the filters and operating the unit without the filters, vent snorkel no longer stops at top of the extended position.

I may be missing part 00635212 described as Distance Holder (diagram number 0134). Does the Distance Holder install at the location shown by the red arrow on the attached photo? Currently, the long screw from the motor makes a knocking sound as the snorkel is extended.

Any help in repairing this unit is greatly appreciated

[img=https://photos.google.com/album/AF1QipMRg9tKa9Ve6SbUPhuIjPn2fUDN710r3HT8al4-/photo/AF1QipMQvyXLg8d1ax4S3W3Ui6yjxPijD2JmhjUDqpas]top of motor screw[/img]ed.