I realize this is an old thread, but how did you remove the worm gear from the little electric motor, or did you replace the motor altogether? Further, before putting in the new outer large metal housing (with pins), the gears (new) and black housing rotate fine with no jams. But after putting in the outer housing, the inner black housing does not rotate and I hear the gears just spinning. I've reassembled and tried tightening the holding screws just slightly all to no avail. I suspect it's the worm gear slipping when the housing is tightened up. Or am I missing something? Any pointers? I added grease and the gears are new except for the worm gear. The assembly order is correct as I took pictures while disassembling.

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'05 E53 X5 4.4i, '97 E39 528, '07 E92 335i, '16 F86 X6M.