What many VW owners don't know is that you have to lubricate the door locking mechanism, a few drops of engine oil with each maintenance ensures that the mechanism works properly.
From the 1967 model onwards, a special opening was made in the door frame exactly at the height of the locking mechanism. This opening is closed by a white plastic cap.
If the cap is still there and has been painted in the body paint, you can be sure that the door mechanism has not been lubricated for a long time. If the hole is still there but the cap is missing, the lock will no longer be in good condition and cleaning is necessary. Then, of course, install a new cap.
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