Can you hear the motor running?


Probably the plastic slide part.

Remove door panel, remove regulator, and have slide (purchased here or from dealer- cheap) riveted onto regulator arm.

When I reassemble, I put new grease on the moving parts.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E